Livestock grazing has a significant impact on natural grasslands,with approximately one-third of the world’s land area dedicated to this industry.Around 20%of global grasslands are highly degraded due to overgrazing,...Livestock grazing has a significant impact on natural grasslands,with approximately one-third of the world’s land area dedicated to this industry.Around 20%of global grasslands are highly degraded due to overgrazing,affecting their productivity and conservation capacity.Best practices are required to ensure sustainable livestock production that supports biodiversity.The Intermediate Disturbance Hypothesis(IDH)suggests that environments with moderate levels of disturbance exhibit a higher species diversity.Moderate grazing can reduce the dominance of certain species,thereby enhancing plant diversity.However,concerns arise regarding the increase of exotic and unpalatable species under moderate grazing levels,complicating grassland conservation efforts.The impact of livestock grazing on the functional structure of grasslands depends on factors such as grazing intensity,livestock species,and environmental conditions.Variations in grazing intensity may increase specific and functional diversity under moderate grazing,potentially masking the presence of invasive exotic species.In the Austral Pampas(Pampean phytogeographic province,Buenos Aires,Argentina),grasslands face various pressures from domestic livestock grazing that endanger their integrity if not properly managed.Therefore,our study aims to investigate potential differences in species richness and diversity,functional diversity,exotic plant abundance,and the number and distribution of plant functional groups across varying grazing intensities.The IDH is utilized as a tool to regulate livestock pressure for grassland conservation.Species and functional diversity indices were used to assess the impact of grazing on grassland diversity.Moderate grazing increased species and functional diversity,while intensively grazed or ungrazed areas showed reduced diversity.Livestock presence influenced the balance between native and exotic plants,with ungrazed areas having higher native plant abundance and grazed areas exhibiting higher exotic plant abundance.Grazing also influenced the composition of functional groups,with grazing-avoiding species being more prevalent in heavily grazed areas.Principal Component Analysis revealed a clear association between vegetation composition and livestock grazing intensity.These findings offer valuable insights into effectively managing grazing intensity for biodiversity conservation purposes.展开更多
We evaluated fruit availability, phytochemical characteristics and mineral content of R. rubiginosa L. rose hips, at two experimental sites in San Luis province: Potrero de los Funes-El Volcán (PF-V) and Estancia...We evaluated fruit availability, phytochemical characteristics and mineral content of R. rubiginosa L. rose hips, at two experimental sites in San Luis province: Potrero de los Funes-El Volcán (PF-V) and Estancia Grande (EG). Plant density was 70 plants/ha (1 ha = 10,000 m<sup>2</sup>) in PF-V and 50 plants/ha in EG. Fruit availability (D<sub>F</sub>) in fresh fruits (FF) was 4.39 kg (PF-V) and 3.10 kg (EG) during March, and decreased during June. Ascorbic acid in FF increased during ripening period, peaking on late April, early May, and diminished 75% - 85% in dried fruits. Total soluble solids in FF ranged from 32.55 to 55.20 °Brix. Elements Ba, Ca, Fe, K, Zn and Cu, determined by inductively coupled plasma optical emission spectrometry (ICP-OES), were significant for human health. Dried fruits maintain a high level of ascorbic acid, a characteristic added to content of mineral elements, particularly calcium content, providing an important nutritional value to R. rubiginosa rose hips.展开更多
Colorectal cancer(CRC)remains the third most prevalent cancer disease and involves a multi-step process in which intestinal cells acquire malignant characteristics.It is well established that the appearance of distal ...Colorectal cancer(CRC)remains the third most prevalent cancer disease and involves a multi-step process in which intestinal cells acquire malignant characteristics.It is well established that the appearance of distal metastasis in CRC patients is the cause of a poor prognosis and treatment failure.Nevertheless,in the last decades,CRC aggressiveness and progression have been attributed to a specific cell population called CRC stem cells(CCSC)with features like tumor initiation capacity,self-renewal capacity,and acquired multidrug resistance.Emerging data highlight the concept of this cell subtype as a plastic entity that has a dynamic status and can be originated from different types of cells through genetic and epigenetic changes.These alterations are modulated by complex and dynamic crosstalk with environmental factors by paracrine signaling.It is known that in the tumor niche,different cell types,structures,and biomolecules coexist and interact with cancer cells favoring cancer growth and development.Together,these components constitute the tumor microenvironment(TME).Most recently,researchers have also deepened the influence of the complex variety of microorganisms that inhabit the intestinal mucosa,collectively known as gut microbiota,on CRC.Both TME and microorganisms participate in inflammatory processes that can drive the initiation and evolution of CRC.Since in the last decade,crucial advances have been made concerning to the synergistic interaction among the TME and gut microorganisms that condition the identity of CCSC,the data exposed in this review could provide valuable insights into the biology of CRC and the development of new targeted therapies.展开更多
Psidium guajava fruits are consumed fresh or processed (beverages, syrup, ice cream, jams and jellies). Guayaba is a fruit highly perishable and susceptible to damage during the postharvest. One strategy to overcome t...Psidium guajava fruits are consumed fresh or processed (beverages, syrup, ice cream, jams and jellies). Guayaba is a fruit highly perishable and susceptible to damage during the postharvest. One strategy to overcome this problem is its processing by using techniques that preserve its organoleptic, nutritive and functional properties and allow getting food with added value. The purpose of this study was to obtain flour from fresh fruits cultivated in Argentina Northwestern by lyophilization and to determine the antioxidant activity and the main phytochemicals present in fresh fruits and flour. Nutritional composition (sugar, protein and fat) and the bioactive phytochemicals (total phenolic compounds, flavonoid phenolic, condensed and hydrolizable tannin, ascorbic acid, pigments such as anthocyanin and carotenoids) as well as fiber content, were evaluated. The flour preserved flavor, aroma and color of pulp from fresh fruits. The flour contained around 30% of sugar, 20% of total protein, 0.5% of fat and high level of crude fiber. Carotenoids and ascorbic acid were the dominant phytochemicals in flour as well as in fresh fruits. The guayaba flour showed antioxidant activity with SC50 values similar to fresh fruits. The flour showed nutraceutical characteristics that are demanded by functional food and could be used as a dietary supplement.展开更多
In this work hollow rectangular microtubes of polypyrrole(PPy)films were potentiostatically electrodeposited on magnesium alloy AZ91D in salicylate solution.The substrate was previously anodized under potentiostatic c...In this work hollow rectangular microtubes of polypyrrole(PPy)films were potentiostatically electrodeposited on magnesium alloy AZ91D in salicylate solution.The substrate was previously anodized under potentiostatic conditions in a molybdate solution in order to improve the adherence of polymer.Finally the duplex film was modified by the incorporation of silver species.The obtained coatings were characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD)and X-ray photoelectron spectroscopies(XPS)and the antimicrobial activity against the bacteria Escherichia coli was evaluated.The corrosion protection properties of the coatings were examined in Ringer solution by monitoring the open circuit potential,polarization techniques and electrochemical spectroscopy(EIS).The duplex coating presents an improved anticorrosive performance with respect to the PPy film.The best results concerning corrosion protection and antibacterial activity were obtained for the silver-modified composite coating.展开更多
Colorectal cancer(CRC)continues to be one of the main causes of death from cancer because patients progress unfavorably due to resistance to current therapies.Dysregulation of the Wnt/β-catenin pathway plays a fundam...Colorectal cancer(CRC)continues to be one of the main causes of death from cancer because patients progress unfavorably due to resistance to current therapies.Dysregulation of the Wnt/β-catenin pathway plays a fundamental role in the genesis and progression of several types of cancer,including CRC.In many subtypes of CRC,hyperactivation of theβ-catenin pathway is associated with mutations of the adenomatous polyposis coli gene.However,it can also be associated with other causes.In recent years,studies of the tumor microenvironment(TME)have demonstrated its importance in the development and progression of CRC.In this tumor nest,several cell types,structures,and biomolecules interact with neoplastic cells to pave the way for the spread of the disease.Cross-communications between tumor cells and the TME are then established primarily through paracrine factors,which trigger the activation of numerous signaling pathways.Crucial advances in the field of oncology have been made in the last decade.This Minireview aims to actualize what is known about the central role of the Wnt/β-catenin pathway in CRC chemoresistance and aggressiveness,focusing on crosscommunication between CRC cells and the TME.Through this analysis,our main objective was to increase the understanding of this complex disease considering a more global context.Since many treatments for advanced CRC fail due to mechanisms involving chemoresistance,the data here exposed and analyzed are of great interest for the development of novel and effective therapies.展开更多
Colorectal cancer(CRC)remains one of the leading causes of mortality from malignant diseases worldwide.In general terms,CRC presents high heterogeneity due to the influence of different genetic and environmental facto...Colorectal cancer(CRC)remains one of the leading causes of mortality from malignant diseases worldwide.In general terms,CRC presents high heterogeneity due to the influence of different genetic and environmental factors;also,the neoplastic cells are strongly influenced by the extracellular matrix and several surrounding cells,known together as the tumor microenvironment(TME).Bidirectional communication takes place between the tumor and the TME through the release of autocrine and paracrine factors.Parathyroid hormone-related peptide(PTHrP)is a cytokine secreted by a wide variety of tissues and is able to regulate several cellular functions both in physiological as well as in pathological processes.It exerts its effects as a paracrine/autocrine factor,although its mode of action is mainly paracrine.It has been shown that this peptide is expressed by several tumors and that the tumor secretion of PTHrP is responsible for the malignant humoral hypercalcemia.Eight years ago,when our research group started studying PTHrP effects in the experimental models derived from intestinal tumors,the literature available at the time addressing the effects of PTHrP on colorectal tumors was limited,and no articles had been published regarding to the paracrine action of PTHrP in CRC cells.Based on this and on our previous findings regarding the role of PTH in CRC cells,our purpose in recent years has been to explore the role of PTHrP in CRC.We analyzed the behavior of CRC cells treated with exogenous PTHrP,focalizing in the study of the following events:Survival,cell cycle progression and proliferation,migration,chemoresistance,tumor-associated angiogenesis,epithelial to mesenchymal transition program and other events also associated with invasion,such us the induction of cancer stem cells features.This work summarizes the major findings obtained by our investigation group using in vitro and in vivo CRC models that evidence the participation of PTHrP in the acquisition of an aggressive phenotype of CRC cells and the molecular mechanisms involved in these processes.Recently,we found that this cytokine induces this malignant behavior not only by its direct action on these intestinal cells but also through its influence on cells derived from TME,promoting a communication between CRC cells and surrounding cells that contributes to the molecular and morphological changes observed in CRC cells.These investigations establish the basis for our next studies in order to address the clinical applicability of our findings.Recognizing the factors and mechanisms that promote invasion in CRC cells,evasion to the cytotoxic effects of current CRC therapies and thus metastasis is decisive for the identification of new markers with the potential to improve early diagnosis and/or to predict prognosis,to predetermine drug resistance and to provide treatment guidelines that include targeted therapies for this disease.展开更多
Background: Annonaceous acetogenins enclose a large number of biological activities, among which the insecticidal stands out. Methods: We report herein the biocide effects of natural acetogenins from Annona squamosa, ...Background: Annonaceous acetogenins enclose a large number of biological activities, among which the insecticidal stands out. Methods: We report herein the biocide effects of natural acetogenins from Annona squamosa, A.?muricata and A. montana seeds: annonacin, cis-annonacin, cis-annonacin-10- one, asimicin, rolliniastatin-2, cherimolin-1, cherimolin-2, almuñequin, and two β-OH acetogenins: laherradurin and itrabin on Spodoptera frugiperda Smith (Lepidoptera: Noctuidae). Also, some acetylated and methoxy methylated ACG derivatives were synthesized and evaluated: annonacin (3 OAc), annonacin (4 OAc), asimicin (3 OAc), rolliniastatin-2 (3 OAc), rolliniastatin-2 (MOM), laherradurin (3 OAc) and itrabin (3 OAc). Results: The natural acetogenin rolliniastatin-2 (100 μg·g-1 of diet) produced the most important toxic action causing 100% mortality of early instar larvae. Derivatization of ACG yielded compounds that produced nutritional alterations. The incorporation of rolliniastatin-2 (3 OAc) and rolliniastatin-2 (3 MOM) (100 μg·g-1) into the artificial diet of Spodoptera frugiperdadisplayed the strongest antifeedant effects causing marked decreasings in larval growth and adult lethal malformations. Conclusion: Natural acetogenins are promising metabolites for insect control. Derivatization of these compounds reduces their toxicity to early instar larvae.展开更多
Toxic and nutritional effects of annonaceous acetogenins and their semisynthetic analogues on Spodoptera frugiperda were evaluated. Structural modification of the natural ACG, blocking the OH flanking THF with MOM, al...Toxic and nutritional effects of annonaceous acetogenins and their semisynthetic analogues on Spodoptera frugiperda were evaluated. Structural modification of the natural ACG, blocking the OH flanking THF with MOM, allowed us to suggest the mode of action of ACG in the membrane. Our study emphasizes the role of the flanking OH and acetyl groups of THF with the membrane hydrophilic polar head groups. They are essential structural factors in the ACG that facilitate the intermolecular interaction that dehydrates the membrane and makes it potentially toxic against Spodoptera frugiperda.展开更多
A treatment based on the acetogenin fraction of the methanol extract of Rollinia occidentalis seeds was applied to soybean crops for three consecutive years. In relation to the control population, the treatment reduce...A treatment based on the acetogenin fraction of the methanol extract of Rollinia occidentalis seeds was applied to soybean crops for three consecutive years. In relation to the control population, the treatment reduced the population of Anticarsia gemmatalis, Rachiplusia nu, Pseudoplusia includens, Loxostege bifidalis and Spodoptera frugiperda to 52% and 65% after 48 h of application at concentrations of 500 and 750 μg/mL respectively, while low toxic effects were detected on natural enemies. The extract treatment at 500 μg/mL and a solution of the annonaceous acetogenin, squamocin, at 50 and 100 μg/mL, were also applied to a corn field to produce 75%, 93% and 100% mortality rates on the population of S. frugiperda, respectively, after 72 h of application. In addition, damages caused by lepidopterans in treated crops were lower than those observed in non treated fields, evaluated by residual biomass. This statement is based on data from trials with the commercially available insecticides lufenuron and cypermethrin.展开更多
To achieve a good production of a crop, it is essential to know the ability of the species to successfully complete two critical stages in the life cycle such as germination and seedling establishment. In this paper w...To achieve a good production of a crop, it is essential to know the ability of the species to successfully complete two critical stages in the life cycle such as germination and seedling establishment. In this paper we study in comparative form structure of the seed, the importance of tegument in dormancy, the effect of accelerated aging on seed germination and viability, and the early and late growth in J. curcas and J. macrocarpa. External morphology of the seeds allow difference and internally also the embryos show evident differences. J. macrocarpa germination is around 0% - 4%. The total removal of tegument showed a 50% increase and the other treatments between 0% - 10%. Aging accelerated by Tetrazolium test allowed a comparative analysis of VP and GP. J. curcas maintains both to 96 h, while J. macrocarpa the seed viability is registered along the all treatment. J. macrocarpa seeds have less synchronicity than those of J. curcas. ABA and JAs were detected in tegument of J. macrocarpa and J. curcas seeds. JA could have a roll in inhibition of germination of J. macrocarpa seeds. Early and late growth, FW and DW of root, hypocotyl, epicotyl and leaf of J. curcas were significantly different in both species.展开更多
A simple,eco-friendly.sensitive and economic flow injection spectrofluorimetric method was developed for the determination of O-(β-hydroxyethyl)rutosidcs.The procedure was based on the use of an anionic surfactant ...A simple,eco-friendly.sensitive and economic flow injection spectrofluorimetric method was developed for the determination of O-(β-hydroxyethyl)rutosidcs.The procedure was based on the use of an anionic surfactant such as sodium dodecyl sulfate to provide an appreciable O-(β-hydroxyethyl)rutosides fluorescence enhancement,increasing considerably the sensitivity of detection.All the variables affecting the fluorescence intensity were studied and optimized.The flow rate was 5 mL/min with detection at 450 nm(after excitation at 346 nm).A linear correlation between drug amount and peak area was established for 0-(β-hydroxyethyl)rulosides in the range of 0.01-200 μg/mL with a detection limit of0.001 μg/mL(s/n = 3).Validation processes were performed by recovering studies with satisfactory results.The new methodology can be employed for the routine analysis of 0-(P-hydroxyethyl)rutosides in bulks as well as in commercial formulations.展开更多
The illicit addition of phosphodiesterase type-5 (PDE-5) inhibitors like sildenafil (Viagra) in product offered as herbal medicine or dietary supplement for male erectile dysfunction has concerned authorities in r...The illicit addition of phosphodiesterase type-5 (PDE-5) inhibitors like sildenafil (Viagra) in product offered as herbal medicine or dietary supplement for male erectile dysfunction has concerned authorities in recent times. In this paper, we proposed a sensitive surfactant-coated Amberlite XADTM resin for sildenafil preconcentration method with spectrofluorimetric detection. Retention capacity of micellar coated XAD resin for sildenafil was studied and the obtained eluate was measured by spectrofluorometer at excitation and emission wavelengths of 350 and 430 nm, respectively. This method allowed the detection of sildenafil at 0.15 ng/mL with linear range of 0.0003-7.0 μg/mL. The method has been successfully applied to the analysis of some local commercially available herbal medicines and urine.展开更多
This is the first comprehensive ultrastructural study on dwarf males with external gametangia in the ge in the genus Oedogonium,from androspore germination to the liberation of mature male gametes.The ultrastructure o...This is the first comprehensive ultrastructural study on dwarf males with external gametangia in the ge in the genus Oedogonium,from androspore germination to the liberation of mature male gametes.The ultrastructure of the process in O.macrandrium Wittrok is similar to that of Bulbochaete hiloensis(Nordstedt)Tiffany,butwith two remarkable differences.In O.macrandrium:(1)instead of a true transverse wall,only condensed mucilage appears between the gametes of each antheridial cell,and (2)the cell wall between the basal cell and the basal most antheridial cell has simple plasmodesmata similar to those present in the transverse walls of vegetative cells,which are absent in B.hiloensis.展开更多
BACKGROUND Parathyroid hormone-related peptide(PTHrP)plays a key role in the development and progression of many tumors.We found that in colorectal cancer(CRC)HCT116 cells,the binding of PTHrP to its receptor PTHR typ...BACKGROUND Parathyroid hormone-related peptide(PTHrP)plays a key role in the development and progression of many tumors.We found that in colorectal cancer(CRC)HCT116 cells,the binding of PTHrP to its receptor PTHR type 1(PTHR1)activates events associated with an aggressive phenotype.In HCT116 cell xenografts,PTHrP modulates the expression of molecular markers linked to tumor progression.Empirical evidence suggests that the Met receptor is involved in the development and evolution of CRC.Based on these data,we hypothesized that the signaling pathway trigged by PTHrP could be involved in the transactivation of Met and consequently in the aggressive behavior of CRC cells.AIM To elucidate the relationship among PTHR1,PTHrP,and Met in CRC models.METHODS For in vitro assays,HCT116 and Caco-2 cells derived from human CRC were incubated in the absence or presence of PTHrP(1-34)(10-8 M).Where indicated,cells were pre-incubated with specific kinase inhibitors or dimethylsulfoxide,the vehicle of the inhibitors.The protein levels were evaluated by Western blot technique.Real-time polymerase chain reaction(RT-qPCR)was carried out to determine the changes in gene expression.Wound healing assay and morpho logical monitoring were performed to evaluate cell migration and changes related to the epithelialmesenchymal transition(EMT),respectively.The number of viable HCT116 cells was counted by trypan blue dye exclusion test to evaluate the effects of irinotecan(CPT-11),oxaliplatin(OXA),or doxorubicin(DOXO)with or without PTHrP.For in vivo tests,HCT116 cell xenografts on 6-wk-old male N:NIH(S)_nu mice received daily intratumoral injections of PTHrP(40μg/kg)in 100μL phosphate-buffered saline(PBS)or the vehicle(PBS)as a control during 20 d.Humanitarian slaughter was carried out and the tumors were removed,weighed,and fixed in a 4%formaldehyde solution for subsequent treatment by immunoassays.To evaluate the expression of molecular markers in human tumor samples,we studied 23 specimens obtained from CRC patients which were treated at the Hospital Interzonal de Graves y Agudos Dr.JoséPenna(Bahía Blanca,Buenos Aires,Argentina)and the Hospital Provincial de Neuquén(Neuquén,Neuquén,Argentina)from January 1990 to December 2007.Seven cases with normal colorectal tissues were assigned to the control group.Tumor tissue samples and clinical histories of patients were analyzed.Paraffin-embedded blocks from primary tumors were reviewed by hematoxylin-eosin staining technique;subsequently,representative histological samples were selected from each patient.From each paraffin block,tumor sections were stained for immunohistochemical detection.The statistical significance of differences was analyzed using proper statistical analysis.The results were considered statistically significant at P<0.05.RESULTS By Western blot analysis and using total Met antibody,we found that PTHrP regulated Met expression in HCT116 cells but not in Caco-2 cells.In HCT116 cells,Met protein levels increased at 30 min(P<0.01)and at 20 h(P<0.01)whereas the levels diminished at 3 min(P<0.05),10 min(P<0.01),and 1 h to 5 h(P<0.01)of PTHrP treatment.Using an active Met antibody,we found that where the protein levels of total Met decreased(3 min,10 min,and 60 min of PTHrP exposure),the status of phosphorylated/activated Met increased(P<0.01)at the same time,suggesting that Met undergoes proteasomal degradation after its phosphorylation/activation by PTHrP.The increment of its protein level after these decreases(at 30 min and 20 h)suggests a modulation of Met expression by PTHrP in order to improve Met levels and this idea is supported by our observation that the cytokine increased Met mRNA levels at least at 15 min in HCT116 cells as revealed by RT-qPCR analysis(P<0.05).We then proceeded to evaluate the signaling pathways that mediate the phosphorylation/activation of Met induced by PTHrP in HCT116 cells.By Western blot technique,we observed that PP1,a specific inhibitor of the activation of the protooncogene protein tyrosine kinase Src,blocked the effect of PTHrP on Met phosphorylation(P<0.05).Furthermore,the selective inhibition of the ERK 1/2 mitogen-activated protein kinase(ERK 1/2 MAPK)using PD98059 and the p38 MAPK using SB203580 diminished the effect of PTHrP on Met phosphorylation/activation(P<0.05).Using SU11274,the specific inhibitor of Met activation,and trypan blue dye exclusion test,Western blot,wound healing assay,and morphological analysis with a microscope,we observed the reversal of cell events induced by PTHrP such as cell proliferation(P<0.05),migration(P<0.05),and the EMT program(P<0.01)in HCT116 cells.Also,PTHrP favored the chemoresistance to CPT-11(P<0.001),OXA(P<0.01),and DOXO(P<0.01)through the Met pathway.Taken together,these findings suggest that Met activated by PTHrP participates in events associated with the aggressive phenotype of CRC cells.By immunohistochemical analysis,we found that PTHrP in HCT116 cell xenografts enhanced the protein expression of Met(0.190±0.014)compared to tumors from control mice(0.110±0.012;P<0.05)and of its own receptor(2.27±0.20)compared to tumors from control mice(1.98±0.14;P<0.01).Finally,assuming that the changes in the expression of PTHrP and its receptor are directly correlated,we investigated the expression of both Met and PTHR1 in biopsies of CRC patients by immunohistochemical analysis.Comparing histologically differentiated tumors with respect to those less differentiated,we found that the labeling intensity for Met and PTHR1 increased and diminished in a gradual manner,respectively(P<0.05).CONCLUSION PTHrP acts through the Met pathway in CRC cells and regulates Met expression in a CRC animal model.More basic and clinical studies are needed to further evaluate the PTHrP/Met relationship.展开更多
Emerging contaminants constitute a set of substances that are released into the environment for which regulations are currently not established for their environmental monitoring, being antimony one of them. A new met...Emerging contaminants constitute a set of substances that are released into the environment for which regulations are currently not established for their environmental monitoring, being antimony one of them. A new methodology for Sb(III) traces monitoring by solid surface fluorescence is proposed. The metal was complexed with alizarine (Az) as fluorosphore reagent in alcaline medium in presence of the bile salt sodium cholate. To isolate the analyte of matrix constituents, a preconcentration/separation strategy on filter paper was introduced prior to determination step. The solid surface fluorescence was measured λem = 450 nm and λexc = 363 nm using a solid sampler holder. Under optimal conditions, the limits of detection and quantification of proposed methodology were 0.08 and 0.24 μg·L-1, respectively, showing a linear range from 0.24 to 304.4 μg·L-1 with good sensitivity and adequate selectivity. It was applied to the Sb(III) traces determination present in drinking water and beverages samples packaged in polyethylene terephthalate (PET) bottles widely consumed in Argentina. The combination of a preconcentration step on common filter paper and the inherent sensitivity of photoluminescent methods have permitted to achieve sensitivity similar to atomic spectroscopies using a lower price instrument typical in control laboratories. Precision and accuracy were tested with excellent agreement. Results were truenessed by ETAAS with satisfactory concordance.展开更多
The aim of this work has been to evaluate the aluminium (Al(III)) traces contents in 24-hour urine samples from subjects with different tobacco smoke expositions using a new methodology with 1,4-dihydroxy-9, 10-anthra...The aim of this work has been to evaluate the aluminium (Al(III)) traces contents in 24-hour urine samples from subjects with different tobacco smoke expositions using a new methodology with 1,4-dihydroxy-9, 10-anthraquinone (Quinizarine, QZ) as a fluorosphore. Biological samples were tested using commercial reagent strips and clinical parameters. Al(III) was determined complexing with QZ followed by a solid phase extraction step using Nylon membranes as a solid support. The analyte was subsequently quantified by solid surface fluorescence (SSF, λem= 573, λexc= 490) with a detection limit of 0.88 μg L-1 and quantification limit of 2.69 μg L-1. The calibration curve was linear from 2.69 to 499.13 μg L-1 Al(III) (R2 = 0.9973). Urine samples were successfully analysed with an average recovery close to 100%. Solid phase extraction step showed efficacy to eliminate foreign ions and the highly fluorescent matrix own of urine. Results were validated by electrothermal atomic absorption spectrometry (ETAAS) with an adequate concordance. The new methodology has low operation cost with simple instrumentation and without organic solvent.展开更多
AIM:To corroborate the capacity of Phyto V7,a complex of phytochemicals,to improve the physical well-being of human immunodeficiency virus-1(HIV-1) infected and acquired immune deficiency syndrome(AIDS) patients not u...AIM:To corroborate the capacity of Phyto V7,a complex of phytochemicals,to improve the physical well-being of human immunodeficiency virus-1(HIV-1) infected and acquired immune deficiency syndrome(AIDS) patients not undergoing antiretroviral treatment.METHODS:Two hundred and thirty nine HIV-1 seropositive male and female voluntary inmates were recruited through the Uruguay National Program of AIDS.The study participants received for 90 consecutive days every eight hours two tablets(760 mg/each) of Phyto V7,containing a mix of the following phytochemicals:flavonols(Kaempferol,Quercetin),flavones(Apigenin,Luteolin),hydroxycinnamic acids(ferrulic acid),carotenoids(Lutein,Lycopene,Beta carotene) and organosulfur compounds,all from vegetal origin.The participants did not receive any antiretroviral treatment during the study.At days 0,30,60 and 90(± 2 d) the participants were evaluated for body mass index(BMI),tolerance to Phyto V7 and Index of Quality of Life based on the Karfnosky scale.ANOVA,Tukey Post-test,χ2 test and Wilcoxon Signed Rank test were used to analyze the effect of treatment.RESULTS:One hundred and nighty nine study participants finished the study.Already after 30 d of Phyto V7 consumption,the weight,BMI and Karnofsky score statistically significantly improved(P < 0.001),and continued to improve until the end of the study.The mean weight gain per participant during the 90 d wasof 1.21 kg(approximately 2% of body weight).The overall increase in the mean Karnofsky score after 90 d was 14.08%.The lower the BMI and Karnofsky score of the participants were at the beginning of the study,the more notorious was the improvement over time.For example,the mean increment of Index of Quality of Life,among the participants with an initial Karnofsky score of 5 or below(n = 33) from day 0 to day 90,was of 35.67%(0.476 ± 0.044 vs 0.645 ± 0.09; P < 0.001).The tolerability to Phyto V7 was very good and no adverse reactions were recorded or reported.CONCLUSION:Administration of the Phyto V7 can be an important tool to improve the well-being of HIV-1 seropositive individuals and AIDS patients,not undergoing antiretroviral treatment.展开更多
2-Hydroxy-4,6-dimethylpyridine-3-carbonitrile and 2-chloro-4,6-dimethylpyridine-3-carbonitrile compounds have been studied from a theoretical point of view in order to know their structural and vibrational properties ...2-Hydroxy-4,6-dimethylpyridine-3-carbonitrile and 2-chloro-4,6-dimethylpyridine-3-carbonitrile compounds have been studied from a theoretical point of view in order to know their structural and vibrational properties in gas and aqueous solution phases by means of Density Functional Theory (DFT) calculations. The stable structures in both media were optimized by using the hybrid B3LYP/6-31G* method and the solvent effects in aqueous solution were studied by using the integral equation formalism of the polarizable continuum model (IEFPCM) employing the selfconsistent reaction field (SCRF) method. Detailed vibrational analyses for both compounds in the two phases were performed combining the DFT calculations with Pulay’s Scaled Quantum Mechanics Force Field (SQMFF) methodology. The different interactions for both compounds were analyzed by means of the bond orders, atomic charges, solvation energies, dipole moments, molecular electrostatic potentials and force constants parameters. The nature of the interactions was studied by using different descriptors.展开更多
There is an increasing interest in food plant with health-giving effects. The aim of this research was to evaluate the phytochemical and nutraceutical profiles of Cyclanthera pedata fruits, a native fruit of the Andea...There is an increasing interest in food plant with health-giving effects. The aim of this research was to evaluate the phytochemical and nutraceutical profiles of Cyclanthera pedata fruits, a native fruit of the Andean region used by Incas communities called achojcha. Soluble protein (SP), total sugar (TS), free phenolic compounds (FPC), ascorbic acid (AA), total monomeric anthocyanin (TMA), condensed and hydrolizable tannin (CT, HT) were evaluated by sprectrophotometric methods in fresh fruits with and without heating and in flour obtained from fruits. Multielemental composition by ICP-MS was done. Antioxidant activity (AOA) was determined by ABTS and Linoleic acid-b-carotene methods. The inhibitory capacity of LOX, a pro-inflammatory enzyme was also analyzed. The achojcha fresh fruits and achojcha flour showed low amount calories. The flour was high in potassium (7400 mg·K/100 g) and low in sodium (77 mg Na/100 g). High levels of FPC (670 mg GAE/100 g) were found together with elevated levels of AA (123 mg AA/ 100 g). The TMA (0.6 mg C3-GE/100 g) as well as HT (3.4 mg PB2E/100 g) were also detected in flour. All preparations obtained with fresh and dried fruits showed AOA with SC50 values between 1.8 to 14.5 μg GAE/mL. Inhibitory capacity on LOX was also demonstrated (IC50 values of 40 μg GAE/mL). The fresh fruits and flour showed nutraceutical characteristics that are demanded by functional food and could be used as dietary supplement.展开更多
基金funded by CONICET(Consejo Nacional de Investigaciones Científicas y Técnicas)and SGCyT(Secretaría General de Ciencia y Tecnología,Universidad Nacional del Sur,Argentina).
文摘Livestock grazing has a significant impact on natural grasslands,with approximately one-third of the world’s land area dedicated to this industry.Around 20%of global grasslands are highly degraded due to overgrazing,affecting their productivity and conservation capacity.Best practices are required to ensure sustainable livestock production that supports biodiversity.The Intermediate Disturbance Hypothesis(IDH)suggests that environments with moderate levels of disturbance exhibit a higher species diversity.Moderate grazing can reduce the dominance of certain species,thereby enhancing plant diversity.However,concerns arise regarding the increase of exotic and unpalatable species under moderate grazing levels,complicating grassland conservation efforts.The impact of livestock grazing on the functional structure of grasslands depends on factors such as grazing intensity,livestock species,and environmental conditions.Variations in grazing intensity may increase specific and functional diversity under moderate grazing,potentially masking the presence of invasive exotic species.In the Austral Pampas(Pampean phytogeographic province,Buenos Aires,Argentina),grasslands face various pressures from domestic livestock grazing that endanger their integrity if not properly managed.Therefore,our study aims to investigate potential differences in species richness and diversity,functional diversity,exotic plant abundance,and the number and distribution of plant functional groups across varying grazing intensities.The IDH is utilized as a tool to regulate livestock pressure for grassland conservation.Species and functional diversity indices were used to assess the impact of grazing on grassland diversity.Moderate grazing increased species and functional diversity,while intensively grazed or ungrazed areas showed reduced diversity.Livestock presence influenced the balance between native and exotic plants,with ungrazed areas having higher native plant abundance and grazed areas exhibiting higher exotic plant abundance.Grazing also influenced the composition of functional groups,with grazing-avoiding species being more prevalent in heavily grazed areas.Principal Component Analysis revealed a clear association between vegetation composition and livestock grazing intensity.These findings offer valuable insights into effectively managing grazing intensity for biodiversity conservation purposes.
文摘We evaluated fruit availability, phytochemical characteristics and mineral content of R. rubiginosa L. rose hips, at two experimental sites in San Luis province: Potrero de los Funes-El Volcán (PF-V) and Estancia Grande (EG). Plant density was 70 plants/ha (1 ha = 10,000 m<sup>2</sup>) in PF-V and 50 plants/ha in EG. Fruit availability (D<sub>F</sub>) in fresh fruits (FF) was 4.39 kg (PF-V) and 3.10 kg (EG) during March, and decreased during June. Ascorbic acid in FF increased during ripening period, peaking on late April, early May, and diminished 75% - 85% in dried fruits. Total soluble solids in FF ranged from 32.55 to 55.20 °Brix. Elements Ba, Ca, Fe, K, Zn and Cu, determined by inductively coupled plasma optical emission spectrometry (ICP-OES), were significant for human health. Dried fruits maintain a high level of ascorbic acid, a characteristic added to content of mineral elements, particularly calcium content, providing an important nutritional value to R. rubiginosa rose hips.
基金Supported by Agencia Nacional de Promoción Científica y Tecnológica,No.PICT-2020-SERIEA-03440 and PICT-2013-1441Consejo Nacional de Investigaciones Científicas y Técnicas,No.PIP11220200103061CO and PIP11220150100350CO+3 种基金Instituto Nacional del Cáncer Asistencia Financiera Ⅱ,RESOL 493/14,No.2002-4395-14-1Instituto Nacional del Cáncer Asistencia Financiera Ⅲ-2016-2017,RESOL-2016-1006-E-APN-MS,No.2002-3862-16-1 CANCERUniversidad Nacional del Sur,No.PGI:24/B230 and PGI:24/B303Fundación Alberto J Roemmers of Argentina.
文摘Colorectal cancer(CRC)remains the third most prevalent cancer disease and involves a multi-step process in which intestinal cells acquire malignant characteristics.It is well established that the appearance of distal metastasis in CRC patients is the cause of a poor prognosis and treatment failure.Nevertheless,in the last decades,CRC aggressiveness and progression have been attributed to a specific cell population called CRC stem cells(CCSC)with features like tumor initiation capacity,self-renewal capacity,and acquired multidrug resistance.Emerging data highlight the concept of this cell subtype as a plastic entity that has a dynamic status and can be originated from different types of cells through genetic and epigenetic changes.These alterations are modulated by complex and dynamic crosstalk with environmental factors by paracrine signaling.It is known that in the tumor niche,different cell types,structures,and biomolecules coexist and interact with cancer cells favoring cancer growth and development.Together,these components constitute the tumor microenvironment(TME).Most recently,researchers have also deepened the influence of the complex variety of microorganisms that inhabit the intestinal mucosa,collectively known as gut microbiota,on CRC.Both TME and microorganisms participate in inflammatory processes that can drive the initiation and evolution of CRC.Since in the last decade,crucial advances have been made concerning to the synergistic interaction among the TME and gut microorganisms that condition the identity of CCSC,the data exposed in this review could provide valuable insights into the biology of CRC and the development of new targeted therapies.
基金the financial support from Consejo de Investigación de la Universidad Nacional de Tucumán(CIUNT 26 D-430)Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET PIP-704)Argentina and Agencia Nacional de Promoción Científica y Técnica(ANPCyT,PICT 1959).
文摘Psidium guajava fruits are consumed fresh or processed (beverages, syrup, ice cream, jams and jellies). Guayaba is a fruit highly perishable and susceptible to damage during the postharvest. One strategy to overcome this problem is its processing by using techniques that preserve its organoleptic, nutritive and functional properties and allow getting food with added value. The purpose of this study was to obtain flour from fresh fruits cultivated in Argentina Northwestern by lyophilization and to determine the antioxidant activity and the main phytochemicals present in fresh fruits and flour. Nutritional composition (sugar, protein and fat) and the bioactive phytochemicals (total phenolic compounds, flavonoid phenolic, condensed and hydrolizable tannin, ascorbic acid, pigments such as anthocyanin and carotenoids) as well as fiber content, were evaluated. The flour preserved flavor, aroma and color of pulp from fresh fruits. The flour contained around 30% of sugar, 20% of total protein, 0.5% of fat and high level of crude fiber. Carotenoids and ascorbic acid were the dominant phytochemicals in flour as well as in fresh fruits. The guayaba flour showed antioxidant activity with SC50 values similar to fresh fruits. The flour showed nutraceutical characteristics that are demanded by functional food and could be used as a dietary supplement.
基金CONICET(PIP-112-201101-00055),ANPCYT(PICT-2012-0141)and Universidad Nacional del Sur(PGI 24/M127),Bahía Blanca,Argentina are acknowledged for financial support
文摘In this work hollow rectangular microtubes of polypyrrole(PPy)films were potentiostatically electrodeposited on magnesium alloy AZ91D in salicylate solution.The substrate was previously anodized under potentiostatic conditions in a molybdate solution in order to improve the adherence of polymer.Finally the duplex film was modified by the incorporation of silver species.The obtained coatings were characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD)and X-ray photoelectron spectroscopies(XPS)and the antimicrobial activity against the bacteria Escherichia coli was evaluated.The corrosion protection properties of the coatings were examined in Ringer solution by monitoring the open circuit potential,polarization techniques and electrochemical spectroscopy(EIS).The duplex coating presents an improved anticorrosive performance with respect to the PPy film.The best results concerning corrosion protection and antibacterial activity were obtained for the silver-modified composite coating.
基金Supported by Agencia Nacional de Promoción Científica y Tecnológica,No. PICT-2013-1441Consejo Nacional de Investigaciones Científicas y Técnicas,No. PIP11220150100350+4 种基金Instituto Nacional del Cáncer Asistencia Financiera ⅡRESOL 493/14, No. 2002-4395-14-1Instituto Nacional del Cáncer Asistencia Financiera Ⅲ-2016-2017, RESOL-2016-1006-E-APN-MS,No. 2002-3862-16-1Universidad Nacional del Sur (PGI)Argentina,No. 24/B230 and No. 24/B303
文摘Colorectal cancer(CRC)continues to be one of the main causes of death from cancer because patients progress unfavorably due to resistance to current therapies.Dysregulation of the Wnt/β-catenin pathway plays a fundamental role in the genesis and progression of several types of cancer,including CRC.In many subtypes of CRC,hyperactivation of theβ-catenin pathway is associated with mutations of the adenomatous polyposis coli gene.However,it can also be associated with other causes.In recent years,studies of the tumor microenvironment(TME)have demonstrated its importance in the development and progression of CRC.In this tumor nest,several cell types,structures,and biomolecules interact with neoplastic cells to pave the way for the spread of the disease.Cross-communications between tumor cells and the TME are then established primarily through paracrine factors,which trigger the activation of numerous signaling pathways.Crucial advances in the field of oncology have been made in the last decade.This Minireview aims to actualize what is known about the central role of the Wnt/β-catenin pathway in CRC chemoresistance and aggressiveness,focusing on crosscommunication between CRC cells and the TME.Through this analysis,our main objective was to increase the understanding of this complex disease considering a more global context.Since many treatments for advanced CRC fail due to mechanisms involving chemoresistance,the data here exposed and analyzed are of great interest for the development of novel and effective therapies.
基金Supported by Agencia Nacional de Promoción Científica y Tecnológica,No. PICT-2013-1441Consejo Nacional de Investigaciones Científicas y Técnicas,No. PIP11220150100350+3 种基金Instituto Nacional del Cáncer,Asistencia financiera Ⅱ,No. 12002-4395-14-1Instituto Nacional del Cáncer,Asistencia Financiera Ⅲ,No. RESOL-2016-1006-E-APN-MSUniversidad Nacional del Sur,Argentina,No. PGI:24/B230PGI:24/B303
文摘Colorectal cancer(CRC)remains one of the leading causes of mortality from malignant diseases worldwide.In general terms,CRC presents high heterogeneity due to the influence of different genetic and environmental factors;also,the neoplastic cells are strongly influenced by the extracellular matrix and several surrounding cells,known together as the tumor microenvironment(TME).Bidirectional communication takes place between the tumor and the TME through the release of autocrine and paracrine factors.Parathyroid hormone-related peptide(PTHrP)is a cytokine secreted by a wide variety of tissues and is able to regulate several cellular functions both in physiological as well as in pathological processes.It exerts its effects as a paracrine/autocrine factor,although its mode of action is mainly paracrine.It has been shown that this peptide is expressed by several tumors and that the tumor secretion of PTHrP is responsible for the malignant humoral hypercalcemia.Eight years ago,when our research group started studying PTHrP effects in the experimental models derived from intestinal tumors,the literature available at the time addressing the effects of PTHrP on colorectal tumors was limited,and no articles had been published regarding to the paracrine action of PTHrP in CRC cells.Based on this and on our previous findings regarding the role of PTH in CRC cells,our purpose in recent years has been to explore the role of PTHrP in CRC.We analyzed the behavior of CRC cells treated with exogenous PTHrP,focalizing in the study of the following events:Survival,cell cycle progression and proliferation,migration,chemoresistance,tumor-associated angiogenesis,epithelial to mesenchymal transition program and other events also associated with invasion,such us the induction of cancer stem cells features.This work summarizes the major findings obtained by our investigation group using in vitro and in vivo CRC models that evidence the participation of PTHrP in the acquisition of an aggressive phenotype of CRC cells and the molecular mechanisms involved in these processes.Recently,we found that this cytokine induces this malignant behavior not only by its direct action on these intestinal cells but also through its influence on cells derived from TME,promoting a communication between CRC cells and surrounding cells that contributes to the molecular and morphological changes observed in CRC cells.These investigations establish the basis for our next studies in order to address the clinical applicability of our findings.Recognizing the factors and mechanisms that promote invasion in CRC cells,evasion to the cytotoxic effects of current CRC therapies and thus metastasis is decisive for the identification of new markers with the potential to improve early diagnosis and/or to predict prognosis,to predetermine drug resistance and to provide treatment guidelines that include targeted therapies for this disease.
文摘Background: Annonaceous acetogenins enclose a large number of biological activities, among which the insecticidal stands out. Methods: We report herein the biocide effects of natural acetogenins from Annona squamosa, A.?muricata and A. montana seeds: annonacin, cis-annonacin, cis-annonacin-10- one, asimicin, rolliniastatin-2, cherimolin-1, cherimolin-2, almuñequin, and two β-OH acetogenins: laherradurin and itrabin on Spodoptera frugiperda Smith (Lepidoptera: Noctuidae). Also, some acetylated and methoxy methylated ACG derivatives were synthesized and evaluated: annonacin (3 OAc), annonacin (4 OAc), asimicin (3 OAc), rolliniastatin-2 (3 OAc), rolliniastatin-2 (MOM), laherradurin (3 OAc) and itrabin (3 OAc). Results: The natural acetogenin rolliniastatin-2 (100 μg·g-1 of diet) produced the most important toxic action causing 100% mortality of early instar larvae. Derivatization of ACG yielded compounds that produced nutritional alterations. The incorporation of rolliniastatin-2 (3 OAc) and rolliniastatin-2 (3 MOM) (100 μg·g-1) into the artificial diet of Spodoptera frugiperdadisplayed the strongest antifeedant effects causing marked decreasings in larval growth and adult lethal malformations. Conclusion: Natural acetogenins are promising metabolites for insect control. Derivatization of these compounds reduces their toxicity to early instar larvae.
文摘Toxic and nutritional effects of annonaceous acetogenins and their semisynthetic analogues on Spodoptera frugiperda were evaluated. Structural modification of the natural ACG, blocking the OH flanking THF with MOM, allowed us to suggest the mode of action of ACG in the membrane. Our study emphasizes the role of the flanking OH and acetyl groups of THF with the membrane hydrophilic polar head groups. They are essential structural factors in the ACG that facilitate the intermolecular interaction that dehydrates the membrane and makes it potentially toxic against Spodoptera frugiperda.
文摘A treatment based on the acetogenin fraction of the methanol extract of Rollinia occidentalis seeds was applied to soybean crops for three consecutive years. In relation to the control population, the treatment reduced the population of Anticarsia gemmatalis, Rachiplusia nu, Pseudoplusia includens, Loxostege bifidalis and Spodoptera frugiperda to 52% and 65% after 48 h of application at concentrations of 500 and 750 μg/mL respectively, while low toxic effects were detected on natural enemies. The extract treatment at 500 μg/mL and a solution of the annonaceous acetogenin, squamocin, at 50 and 100 μg/mL, were also applied to a corn field to produce 75%, 93% and 100% mortality rates on the population of S. frugiperda, respectively, after 72 h of application. In addition, damages caused by lepidopterans in treated crops were lower than those observed in non treated fields, evaluated by residual biomass. This statement is based on data from trials with the commercially available insecticides lufenuron and cypermethrin.
文摘To achieve a good production of a crop, it is essential to know the ability of the species to successfully complete two critical stages in the life cycle such as germination and seedling establishment. In this paper we study in comparative form structure of the seed, the importance of tegument in dormancy, the effect of accelerated aging on seed germination and viability, and the early and late growth in J. curcas and J. macrocarpa. External morphology of the seeds allow difference and internally also the embryos show evident differences. J. macrocarpa germination is around 0% - 4%. The total removal of tegument showed a 50% increase and the other treatments between 0% - 10%. Aging accelerated by Tetrazolium test allowed a comparative analysis of VP and GP. J. curcas maintains both to 96 h, while J. macrocarpa the seed viability is registered along the all treatment. J. macrocarpa seeds have less synchronicity than those of J. curcas. ABA and JAs were detected in tegument of J. macrocarpa and J. curcas seeds. JA could have a roll in inhibition of germination of J. macrocarpa seeds. Early and late growth, FW and DW of root, hypocotyl, epicotyl and leaf of J. curcas were significantly different in both species.
基金the National University of San Luis(Project 22/Q228)INQUISAL-CONICET(Instituto de Quimica de San Luis-Consejo Nacional de Investigaciones Cientificas y Tecnicas, PIP-CONICET 11220100100405) for the financial support
文摘A simple,eco-friendly.sensitive and economic flow injection spectrofluorimetric method was developed for the determination of O-(β-hydroxyethyl)rutosidcs.The procedure was based on the use of an anionic surfactant such as sodium dodecyl sulfate to provide an appreciable O-(β-hydroxyethyl)rutosides fluorescence enhancement,increasing considerably the sensitivity of detection.All the variables affecting the fluorescence intensity were studied and optimized.The flow rate was 5 mL/min with detection at 450 nm(after excitation at 346 nm).A linear correlation between drug amount and peak area was established for 0-(β-hydroxyethyl)rulosides in the range of 0.01-200 μg/mL with a detection limit of0.001 μg/mL(s/n = 3).Validation processes were performed by recovering studies with satisfactory results.The new methodology can be employed for the routine analysis of 0-(P-hydroxyethyl)rutosides in bulks as well as in commercial formulations.
基金INQUISAL-CONICET (Instituto de Química de San Luis-Consejo Nacional de Investigaciones Científicas y Tecnológicas)FONCYT (Fondo Nacional de Ciencia y Tecnología)the National University of San Luis (Projects SECyT-UNSL 22/Q828 and PIP-CONICET 11220100100405) for their financial support
文摘The illicit addition of phosphodiesterase type-5 (PDE-5) inhibitors like sildenafil (Viagra) in product offered as herbal medicine or dietary supplement for male erectile dysfunction has concerned authorities in recent times. In this paper, we proposed a sensitive surfactant-coated Amberlite XADTM resin for sildenafil preconcentration method with spectrofluorimetric detection. Retention capacity of micellar coated XAD resin for sildenafil was studied and the obtained eluate was measured by spectrofluorometer at excitation and emission wavelengths of 350 and 430 nm, respectively. This method allowed the detection of sildenafil at 0.15 ng/mL with linear range of 0.0003-7.0 μg/mL. The method has been successfully applied to the analysis of some local commercially available herbal medicines and urine.
基金Funds were provided by the Universidad Nacional del Sur(UNS,SGCyT),Grant PGI 24/B151 to EJC.
文摘This is the first comprehensive ultrastructural study on dwarf males with external gametangia in the ge in the genus Oedogonium,from androspore germination to the liberation of mature male gametes.The ultrastructure of the process in O.macrandrium Wittrok is similar to that of Bulbochaete hiloensis(Nordstedt)Tiffany,butwith two remarkable differences.In O.macrandrium:(1)instead of a true transverse wall,only condensed mucilage appears between the gametes of each antheridial cell,and (2)the cell wall between the basal cell and the basal most antheridial cell has simple plasmodesmata similar to those present in the transverse walls of vegetative cells,which are absent in B.hiloensis.
基金Supported by the Agencia Nacional de Promoción Científica y TecnológicaNo. PICT-2013-1441+8 种基金Consejo Nacional de Investigaciones Científicas y TécnicasNo. PIP11220150100350Instituto Nacional del Cáncer Asistencia Financiera ⅡRESOL 493/14, No. 2002-4395-14-1Instituto Nacional del Cáncer Asistencia Financiera Ⅲ-2016-2017, RESOL-2016-1006-E-APN-MSNo. 2002-3862-16-1 CANCERUniversidad Nacional del SurNo. PGI:24/B230 and No. PGI:24/B303Fundación Alberto J. Roemmers of Argentina
文摘BACKGROUND Parathyroid hormone-related peptide(PTHrP)plays a key role in the development and progression of many tumors.We found that in colorectal cancer(CRC)HCT116 cells,the binding of PTHrP to its receptor PTHR type 1(PTHR1)activates events associated with an aggressive phenotype.In HCT116 cell xenografts,PTHrP modulates the expression of molecular markers linked to tumor progression.Empirical evidence suggests that the Met receptor is involved in the development and evolution of CRC.Based on these data,we hypothesized that the signaling pathway trigged by PTHrP could be involved in the transactivation of Met and consequently in the aggressive behavior of CRC cells.AIM To elucidate the relationship among PTHR1,PTHrP,and Met in CRC models.METHODS For in vitro assays,HCT116 and Caco-2 cells derived from human CRC were incubated in the absence or presence of PTHrP(1-34)(10-8 M).Where indicated,cells were pre-incubated with specific kinase inhibitors or dimethylsulfoxide,the vehicle of the inhibitors.The protein levels were evaluated by Western blot technique.Real-time polymerase chain reaction(RT-qPCR)was carried out to determine the changes in gene expression.Wound healing assay and morpho logical monitoring were performed to evaluate cell migration and changes related to the epithelialmesenchymal transition(EMT),respectively.The number of viable HCT116 cells was counted by trypan blue dye exclusion test to evaluate the effects of irinotecan(CPT-11),oxaliplatin(OXA),or doxorubicin(DOXO)with or without PTHrP.For in vivo tests,HCT116 cell xenografts on 6-wk-old male N:NIH(S)_nu mice received daily intratumoral injections of PTHrP(40μg/kg)in 100μL phosphate-buffered saline(PBS)or the vehicle(PBS)as a control during 20 d.Humanitarian slaughter was carried out and the tumors were removed,weighed,and fixed in a 4%formaldehyde solution for subsequent treatment by immunoassays.To evaluate the expression of molecular markers in human tumor samples,we studied 23 specimens obtained from CRC patients which were treated at the Hospital Interzonal de Graves y Agudos Dr.JoséPenna(Bahía Blanca,Buenos Aires,Argentina)and the Hospital Provincial de Neuquén(Neuquén,Neuquén,Argentina)from January 1990 to December 2007.Seven cases with normal colorectal tissues were assigned to the control group.Tumor tissue samples and clinical histories of patients were analyzed.Paraffin-embedded blocks from primary tumors were reviewed by hematoxylin-eosin staining technique;subsequently,representative histological samples were selected from each patient.From each paraffin block,tumor sections were stained for immunohistochemical detection.The statistical significance of differences was analyzed using proper statistical analysis.The results were considered statistically significant at P<0.05.RESULTS By Western blot analysis and using total Met antibody,we found that PTHrP regulated Met expression in HCT116 cells but not in Caco-2 cells.In HCT116 cells,Met protein levels increased at 30 min(P<0.01)and at 20 h(P<0.01)whereas the levels diminished at 3 min(P<0.05),10 min(P<0.01),and 1 h to 5 h(P<0.01)of PTHrP treatment.Using an active Met antibody,we found that where the protein levels of total Met decreased(3 min,10 min,and 60 min of PTHrP exposure),the status of phosphorylated/activated Met increased(P<0.01)at the same time,suggesting that Met undergoes proteasomal degradation after its phosphorylation/activation by PTHrP.The increment of its protein level after these decreases(at 30 min and 20 h)suggests a modulation of Met expression by PTHrP in order to improve Met levels and this idea is supported by our observation that the cytokine increased Met mRNA levels at least at 15 min in HCT116 cells as revealed by RT-qPCR analysis(P<0.05).We then proceeded to evaluate the signaling pathways that mediate the phosphorylation/activation of Met induced by PTHrP in HCT116 cells.By Western blot technique,we observed that PP1,a specific inhibitor of the activation of the protooncogene protein tyrosine kinase Src,blocked the effect of PTHrP on Met phosphorylation(P<0.05).Furthermore,the selective inhibition of the ERK 1/2 mitogen-activated protein kinase(ERK 1/2 MAPK)using PD98059 and the p38 MAPK using SB203580 diminished the effect of PTHrP on Met phosphorylation/activation(P<0.05).Using SU11274,the specific inhibitor of Met activation,and trypan blue dye exclusion test,Western blot,wound healing assay,and morphological analysis with a microscope,we observed the reversal of cell events induced by PTHrP such as cell proliferation(P<0.05),migration(P<0.05),and the EMT program(P<0.01)in HCT116 cells.Also,PTHrP favored the chemoresistance to CPT-11(P<0.001),OXA(P<0.01),and DOXO(P<0.01)through the Met pathway.Taken together,these findings suggest that Met activated by PTHrP participates in events associated with the aggressive phenotype of CRC cells.By immunohistochemical analysis,we found that PTHrP in HCT116 cell xenografts enhanced the protein expression of Met(0.190±0.014)compared to tumors from control mice(0.110±0.012;P<0.05)and of its own receptor(2.27±0.20)compared to tumors from control mice(1.98±0.14;P<0.01).Finally,assuming that the changes in the expression of PTHrP and its receptor are directly correlated,we investigated the expression of both Met and PTHR1 in biopsies of CRC patients by immunohistochemical analysis.Comparing histologically differentiated tumors with respect to those less differentiated,we found that the labeling intensity for Met and PTHR1 increased and diminished in a gradual manner,respectively(P<0.05).CONCLUSION PTHrP acts through the Met pathway in CRC cells and regulates Met expression in a CRC animal model.More basic and clinical studies are needed to further evaluate the PTHrP/Met relationship.
文摘Emerging contaminants constitute a set of substances that are released into the environment for which regulations are currently not established for their environmental monitoring, being antimony one of them. A new methodology for Sb(III) traces monitoring by solid surface fluorescence is proposed. The metal was complexed with alizarine (Az) as fluorosphore reagent in alcaline medium in presence of the bile salt sodium cholate. To isolate the analyte of matrix constituents, a preconcentration/separation strategy on filter paper was introduced prior to determination step. The solid surface fluorescence was measured λem = 450 nm and λexc = 363 nm using a solid sampler holder. Under optimal conditions, the limits of detection and quantification of proposed methodology were 0.08 and 0.24 μg·L-1, respectively, showing a linear range from 0.24 to 304.4 μg·L-1 with good sensitivity and adequate selectivity. It was applied to the Sb(III) traces determination present in drinking water and beverages samples packaged in polyethylene terephthalate (PET) bottles widely consumed in Argentina. The combination of a preconcentration step on common filter paper and the inherent sensitivity of photoluminescent methods have permitted to achieve sensitivity similar to atomic spectroscopies using a lower price instrument typical in control laboratories. Precision and accuracy were tested with excellent agreement. Results were truenessed by ETAAS with satisfactory concordance.
文摘The aim of this work has been to evaluate the aluminium (Al(III)) traces contents in 24-hour urine samples from subjects with different tobacco smoke expositions using a new methodology with 1,4-dihydroxy-9, 10-anthraquinone (Quinizarine, QZ) as a fluorosphore. Biological samples were tested using commercial reagent strips and clinical parameters. Al(III) was determined complexing with QZ followed by a solid phase extraction step using Nylon membranes as a solid support. The analyte was subsequently quantified by solid surface fluorescence (SSF, λem= 573, λexc= 490) with a detection limit of 0.88 μg L-1 and quantification limit of 2.69 μg L-1. The calibration curve was linear from 2.69 to 499.13 μg L-1 Al(III) (R2 = 0.9973). Urine samples were successfully analysed with an average recovery close to 100%. Solid phase extraction step showed efficacy to eliminate foreign ions and the highly fluorescent matrix own of urine. Results were validated by electrothermal atomic absorption spectrometry (ETAAS) with an adequate concordance. The new methodology has low operation cost with simple instrumentation and without organic solvent.
文摘AIM:To corroborate the capacity of Phyto V7,a complex of phytochemicals,to improve the physical well-being of human immunodeficiency virus-1(HIV-1) infected and acquired immune deficiency syndrome(AIDS) patients not undergoing antiretroviral treatment.METHODS:Two hundred and thirty nine HIV-1 seropositive male and female voluntary inmates were recruited through the Uruguay National Program of AIDS.The study participants received for 90 consecutive days every eight hours two tablets(760 mg/each) of Phyto V7,containing a mix of the following phytochemicals:flavonols(Kaempferol,Quercetin),flavones(Apigenin,Luteolin),hydroxycinnamic acids(ferrulic acid),carotenoids(Lutein,Lycopene,Beta carotene) and organosulfur compounds,all from vegetal origin.The participants did not receive any antiretroviral treatment during the study.At days 0,30,60 and 90(± 2 d) the participants were evaluated for body mass index(BMI),tolerance to Phyto V7 and Index of Quality of Life based on the Karfnosky scale.ANOVA,Tukey Post-test,χ2 test and Wilcoxon Signed Rank test were used to analyze the effect of treatment.RESULTS:One hundred and nighty nine study participants finished the study.Already after 30 d of Phyto V7 consumption,the weight,BMI and Karnofsky score statistically significantly improved(P < 0.001),and continued to improve until the end of the study.The mean weight gain per participant during the 90 d wasof 1.21 kg(approximately 2% of body weight).The overall increase in the mean Karnofsky score after 90 d was 14.08%.The lower the BMI and Karnofsky score of the participants were at the beginning of the study,the more notorious was the improvement over time.For example,the mean increment of Index of Quality of Life,among the participants with an initial Karnofsky score of 5 or below(n = 33) from day 0 to day 90,was of 35.67%(0.476 ± 0.044 vs 0.645 ± 0.09; P < 0.001).The tolerability to Phyto V7 was very good and no adverse reactions were recorded or reported.CONCLUSION:Administration of the Phyto V7 can be an important tool to improve the well-being of HIV-1 seropositive individuals and AIDS patients,not undergoing antiretroviral treatment.
文摘2-Hydroxy-4,6-dimethylpyridine-3-carbonitrile and 2-chloro-4,6-dimethylpyridine-3-carbonitrile compounds have been studied from a theoretical point of view in order to know their structural and vibrational properties in gas and aqueous solution phases by means of Density Functional Theory (DFT) calculations. The stable structures in both media were optimized by using the hybrid B3LYP/6-31G* method and the solvent effects in aqueous solution were studied by using the integral equation formalism of the polarizable continuum model (IEFPCM) employing the selfconsistent reaction field (SCRF) method. Detailed vibrational analyses for both compounds in the two phases were performed combining the DFT calculations with Pulay’s Scaled Quantum Mechanics Force Field (SQMFF) methodology. The different interactions for both compounds were analyzed by means of the bond orders, atomic charges, solvation energies, dipole moments, molecular electrostatic potentials and force constants parameters. The nature of the interactions was studied by using different descriptors.
基金The authors thank the inhabitants of the areas of study for their cooperation and acknowledge the financial sup-port from Consejo de Investigación de la Universidad Nacional de Tucumán(CIUNT 26 D-430)Argentina and Consejo Nacional de Investigaciones Científicas y Téc-nicas(CONICET PIP-704),Argentina.
文摘There is an increasing interest in food plant with health-giving effects. The aim of this research was to evaluate the phytochemical and nutraceutical profiles of Cyclanthera pedata fruits, a native fruit of the Andean region used by Incas communities called achojcha. Soluble protein (SP), total sugar (TS), free phenolic compounds (FPC), ascorbic acid (AA), total monomeric anthocyanin (TMA), condensed and hydrolizable tannin (CT, HT) were evaluated by sprectrophotometric methods in fresh fruits with and without heating and in flour obtained from fruits. Multielemental composition by ICP-MS was done. Antioxidant activity (AOA) was determined by ABTS and Linoleic acid-b-carotene methods. The inhibitory capacity of LOX, a pro-inflammatory enzyme was also analyzed. The achojcha fresh fruits and achojcha flour showed low amount calories. The flour was high in potassium (7400 mg·K/100 g) and low in sodium (77 mg Na/100 g). High levels of FPC (670 mg GAE/100 g) were found together with elevated levels of AA (123 mg AA/ 100 g). The TMA (0.6 mg C3-GE/100 g) as well as HT (3.4 mg PB2E/100 g) were also detected in flour. All preparations obtained with fresh and dried fruits showed AOA with SC50 values between 1.8 to 14.5 μg GAE/mL. Inhibitory capacity on LOX was also demonstrated (IC50 values of 40 μg GAE/mL). The fresh fruits and flour showed nutraceutical characteristics that are demanded by functional food and could be used as dietary supplement.