Effects of Beta; 1-adrenoceptors in the Basolateral Amygdala on Spatial Memory, Passive Avoidance, Long-term Potentiation and Neuronal Arborization in the Hippocampal CA1 Region in Response to Unavoidable Stress

Abstract Norepinephrine in the basolateral amygdala (BLA) plays a pivotal role in mediating the effects of stress on memory functions in the hippocampus, however, the functional contribution of β1-adrenergic receptors on the BLA inputs to the CA1 region of hippocampus and memory function are not well understood. In the present study the role of β1-adrenoreceptor in the BLA on memory, neuronal arborization and long-term potentiation (LTP) in the CA1 region of hippocampus was examined by infusion the β1-adrenoreceptor agonist (Dobutamine; 0.5µl/side) or antagonist (Atenolol; 0.25µL/side) bilaterally into the BLA before foot-shock stress. Passive avoidance test results showed that Step-through latency time was significantly decreased in the stress group rats one, four and seven days after the stress, which intra-BLA injection of Atenolol or Dobutamine before stress couldn't attenuate this reduction. Barnes-maze results revealed that infusion of Dobutamine and Atenolol significantly reduced spatial memory indicators such as increased latency time, the number of errors and the distance traveling to achieve the target hole in the stress group. These learning impairments in stress rats correlated with a reduction of LTP in hippocampal CA1 synapses in-vivo, which infusion of Dobutamine and Atenolol couldn't attenuate the population spike amplitude and mean-field excitatory postsynaptic potentials (fEPSP) slope reduction induced by stress. Also, the Golgi-Cox staining demonstrated that infusion of Atenolol attenuated stress decreased CA1 region dendritic and axonal arborization. These results suggest that β1-adrenergic receptors activation or block seem to exacerbate stress-induced hippocampal memory deficits and this effect is independent of CA1 LTP modulation.

Transcriptome analysis of phosphorus stress responsiveness in the seedlings of Dongxiang wild rice (Oryza rufipogon Griff.)

Abstract Background: Low phosphorus availability is a major factor restricting rice growth. Dongxiang wild rice (Oryza rufipogon Griff.) has many useful genes lacking in cultivated rice, including stress resistance to phosphorus deficiency, cold, salt and drought, which is considered to be a precious germplasm resource for rice breeding. However, the molecular mechanism of regulation of phosphorus deficiency tolerance is not clear. Results: In this study, cDNA libraries were constructed from the leaf and root tissues of phosphorus stressed and untreated Dongxiang wild rice seedlings, and transcriptome sequencing was performed with the goal of elucidating the molecular mechanisms involved in phosphorus stress response. The results indicated that 1184 transcripts were differentially expressed in the leaves (323 up-regulated and 861 down-regulated) and 986 transcripts were differentially expressed in the roots (756 up-regulated and 230 down-regulated). 43 genes were up-regulated both in leaves and roots, 38 genes were up-regulated in roots but down-regulated in leaves, and only 2 genes were down-regulated in roots but up-regulated in leaves. Among these differentially expressed genes, the detection of many transcription factors and functional genes demonstrated that multiple regulatory pathways were involved in phosphorus deficiency tolerance. Meanwhile, the differentially expressed genes were also annotated with gene ontology terms and key pathways via functional classification and Kyoto Encyclopedia of Gene and Genomes pathway mapping, respectively. A set of the most important candidate genes was then identified by combining the differentially expressed genes found in the present study with previously identified phosphorus deficiency tolerance quantitative trait loci. Conclusion: The present work provides abundant genomic information for functional dissection of the phosphorus deficiency resistance of Dongxiang wild rice, which will be help to understand the biological regulatory mechanisms of phosphorus deficiency tolerance in Dongxiang wild rice.

Selenocysteine modulates resistance to environmental stress and confers anti-aging effects in C. elegans

OBJECTIVE: The free radical theory of aging suggests that cellular oxidative damage caused by free radicals is a leading cause of aging. In the present study, we examined the effects of a well-known anti-oxidant amino acid derivative, selenocysteine, in response to environmental stress and aging using Caenorhabditis elegans as a model system. METHOD: The response to oxidative stress induced by H2O2 or ultraviolet irradiation was compared between the untreated control and selenocysteine-treated groups. The effect of selenocysteine on lifespan and fertility was then determined. To examine the effect of selenocysteine on muscle aging, we monitored the change in motility with aging in both the untreated control and selenocysteine-treated groups. RESULTS: Dietary supplementation with selenocysteine significantly increased resistance to oxidative stress. Survival after ultraviolet irradiation was also increased by supplementation with selenocysteine. Treatment with selenocysteine confers a longevity phenotype without an accompanying reduction in fertility, which is frequently observed in lifespan-extending interventions as a trade-off in C. elegans. In addition, the age-related decline in motility was significantly delayed by supplementation of selenocysteine. CONCLUSION: These findings suggest that dietary supplementation of selenocysteine can modulate response to stressors and lead to lifespan extension, thus supporting the free radical theory of aging.

Distorsión morfológica isquémica de la onda T en la centellografía de perfusión miocárdica con estrés vasodilatador / Ischemic T wave distortion associated with vasodilator-stress myocardial perfusion imaging

Los protocolos que utilizan vasodilatadores para inducir isquemia en la centellografía de perfusión miocárdica han demostrado una exactitud diagnóstica elevada e incidencia muy baja de complicaciones graves. Sin embargo, el significado fisiológico y valor diagnóstico de diversas alteraciones electrocardiográficas asociadas al estrés vasodilatador ha sido escasamente evaluado más allá del segmento ST. Describimos cinco pacientes que presentan distorsión morfológica de la onda T en derivaciones electrocardiográficas torácicas asociada a diversos defectos de perfusión, discutiendo los potenciales aportes de estos cambios al diagnóstico y cuantificación de la isquemia miocárdica en los estudios de imagen que utilizan estrés con vasodilatadores.

The protocols using vasodilators to induce ischemia on myocardial perfusion scintigraphy have shown a high diagnostic accuracy and a very low incidence of serious complications. However, the physiological significance and diagnostic value of various electrocardiographic changes associated with vasodilator stress has not been deeply evaluated beyond the ST-segment. Five clinical cases presenting morphological distortion of the T-wave in electrocardiographic chest leads associated with varying degrees of perfusion defects are described, discussing potential contributions of these changes to the diagnosis and quantification of myocardial ischemia in imaging studies using vasodilator stress.

Effects of levamisole on immune responses and resistance against density stress in rainbow trout fingerling [Oncorhynchus my kiss]

Background: It is necessary to potentiate the immune system of fishes against stresses in farms

Objectives: This study was carried out to address the potential effect of Levamisole on immune system of rainbow trout against density stress

Methods: 1500 fish [average weight of 50 g] were divided into 5 test groups, in which each test group was repeated three times with average density of 33 kg/m[3]. They were fed with commercial diet supplemented with Levamisole at concentrations of 0 [control], 100, 250, 500 and 1000 mg / kg for a period of 45 days. The fishes of all groups were then fed with Levamisole free diet and exposed to 2 and 3-fold density stress for the following 15 days. Blood samples were collected on days 0, 15, 30, 45 and 60 to evaluate the serum compliment and lysozyme activity as well as total immunoglobulins

Results: The results showed that all used concentrations of Levamisole just had significant effect on compliment activity after 45 days feeding period [p<0.05]. Higher levels of lysozyme and complement activity as well as total immunoglobulin were observed in 1000 mg/kg Levamisole treated group when exposed to density stresses 2 and 3-fold at the end of trial [day 60] [p<0.05]. The highest overall survival was found in group which was treated with 1000 mg/kg of Levamisole

Conclusions: Our results revealed that using 0/1% Levamisole as an im-munostimulator in commercial diet could potentiate rainbow trout against outbreak of high density stresses and increase its overall survival

The association of Hsp90 expression induced by aspirin with anti-stress damage in chicken myocardial cells

The protective effect of aspirin during exposure to heat stress in broiler chickens was investigated. We assayed pathological damage, expression and distribution of Hsp90 protein and hsp90 mRNA expression in chicken heart tissues after oral administration of aspirin following exposure to high temperature for varying times. Heat stress induced increases in plasma aspartate aminotransferase, creatine kinase and lactate dehydrogenase activities while causing severe heart damage, which was characterized by granular and vacuolar degeneration, nuclear shrinkage and even myocardium fragmentation in cardiac muscle fibers. After aspirin administration, myocardial cells showed fewer pathological lesions than broilers treated with heat alone. A high positive Hsp90 signal was always detected in the nuclei of myocardial cells from broilers treated with aspirin, while in myocardial cells treated with heat alone, Hsp90 in the nuclei decreased, as did that in the cytoplasm. Aspirin induced rapid and significant synthesis of Hsp90 before and at the initial phase of heat stress, and significant expression of hsp90 mRNA was stimulated throughout the experiment when compared with cells exposed to heat stress alone. Thus, specific pre-induction of Hsp90 in cardiovascular tissue was useful for resisting heat stress damage because it produced stable damage-related enzymes and fewer pathologic changes.

Rosmarinus officinalis L. increases Caenorhabditis elegans stress resistance and longevity in a DAF-16, HSF-1 and SKN-1-dependent manner

Improving overall health and quality of life, preventing diseases and increasing life expectancy are key concerns in the field of public health. The search for antioxidants that can inhibit oxidative damage in cells has received a lot of attention. Rosmarinus officinalis L. represents an exceptionally rich source of bioactive compounds with pharmacological properties. In the present study, we explored the effects of the ethanolic extract of R. officinalis (eeRo) on stress resistance and longevity using the non-parasitic nematode Caenorhabditis elegans as a model. We report for the first time that eeRo increased resistance against oxidative and thermal stress and extended C. elegans longevity in an insulin/IGF signaling pathway-dependent manner. These data emphasize the eeRo beneficial effects on C. elegans under stress.

Effect of (+)-dehydrofukinone on GABAA receptors and stress response in fish model

(+)-Dehydrofukinone (DHF) is a major component of the essential oil of Nectandra grandiflora (Lauraceae), and exerts a depressant effect on the central nervous system of fish. However, the neuronal mechanism underlying DHF action remains unknown. This study aimed to investigate the action of DHF on GABAA receptors using a silver catfish (Rhamdia quelen) model. Additionally, we investigated the effect of DHF exposure on stress-induced cortisol modulation. Chemical identification was performed using gas chromatography-mass spectrometry and purity was evaluated using gas chromatography with a flame ionization detector. To an aquarium, we applied between 2.5 and 50 mg/L DHF diluted in ethanol, in combination with 42.7 mg/L diazepam. DHF within the range of 10-20 mg/L acted collaboratively in combination with diazepam, but the sedative action of DHF was reversed by 3 mg/L flumazenil. Additionally, fish exposed for 24 h to 2.5-20 mg/L DHF showed no side effects and there was sustained sedation during the first 12 h of drug exposure with 10-20 mg/L DHF. DHF pretreatment did not increase plasma cortisol levels in fish subjected to a stress protocol. Moreover, the stress-induced cortisol peak was absent following pretreatment with 20 mg/L DHF. DHF proved to be a relatively safe sedative or anesthetic, which interacts with GABAergic and cortisol pathways in fish.

Total clipless cholecystectomy by means of harmonic sealing / Colecistectomia laparoscópica totalmente ultrassônica sem uso de clipe metálico

BACKGROUND: In traditional laparoscopic cholecistectomy, the cystic duct and artery are commonly closed by metallic clips just before their division. Although the placement of these clips for occluding cystic artery and duct can be considered safe, biliary leaks and bleeding may occur especially by its dislodgement. AIM: To report a prospective case-series in total clipless cholecystectomy by means of harmonic shears for closure and division of the artery and cystic duct as well removal of the gallbladder from the liver. METHODS: Was evaluate a series of 125 patients who underwent laparoscopic cholecystectomy where the sealing and division of cystic artery and duct was carried out only by harmonic shears. The intact extracted gallbladder was submitted to a reverse pressure test for assessment of the technique safety by means of CO2 insuflation. RESULTS: The most common indication for surgery was gallstones. The mean operative time was 26 min and all gallbladders were dissected intact from the liver bed. There was no mortality and the overall morbidity rate was 0.8% with no hemorrhage or leaks. The reverse pressure test showed that all specimens support at least 36-mmHg of pressure without leaking. CONCLUSION: The harmonic shears is effective and safe in laparoscopic cholecystectomy as a sole instrument for sealing and division of the artery and cystic duct. The main advantages could be related to the safety and decreased operative time. .

RACIONAL: A colecistectomia laparoscópica na técnica tradicional oclui o ducto cístico e a artéria cística por clipes cirúrgicos, que podem se deslocar ou desprender no pós-operatório, possibilitando a ocorrência de fístula biliar ou hemorragia. OBJETIVO: Relato prospectivo de série de casos de colecistectomias laparoscópicas sem uso de clipe cirúrgico, sendo que a ligadura e secção da artéria cística e do ducto cístico foram realizadas por meio de bisturi ultrassônico. MÉTODO: Foram incluídos 125 pacientes submetidos à colecistectomia laparoscópica sem utilização de clipe cirúrgico metálico, onde a ligadura da artéria e do ducto cístico e também a remoção da vesícula biliar de seu leito hepático foram realizadas por meio de tesoura ultrassônica. Realizou-se teste de pressão reversa na vesícula biliar removida intacta do leito hepático para verificar a segurança da técnica. RESULTADOS: A principal indicação cirúrgica foi a colelitíase. O tempo cirúrgico médio foi de 26 min e todas as vesículas biliares foram retiradas intactas do leito hepático. Não houve mortalidade e a taxa global de morbidade foi de 0,8%, sem hemorragias ou fístulas. O teste de pressão reversa mostrou que o ducto cístico ocluído pelo bisturi harmônico suportou ao pelo menos 36 mmHg de pressão sem que ocorresse nenhum vazamento. CONCLUSÃO: O bisturi harmônico é eficaz e seguro em colecistectomias laparoscópicas eletivas como um instrumento único para ocluir e seccionar tanto a artéria cística quanto o ducto cístico. Vantagens podem ser apontadas ao método com relação a sua segurança e diminuição do tempo cirúrgico. .

Subarachnoid clonidine and trauma response in cardiac surgery with cardiopulmonary bypass / Clonidina subaracnóidea e resposta ao trauma em cirurgias cardíacas com circulação extracorpórea / Clonidina subaracnoidea y respuesta al trauma en cirugías cardíacas con circulación extracorpórea

Background and objectives: The intense trauma response triggered by cardiopulmonary bypass can lead to increased morbidity and mortality. The present study evaluated whether clonidine, a drug of the class of α-2 agonists, administered by spinal route, without association with local anesthetics or opioids, reduces this response in cardiac surgery with cardiopulmonary bypass. Method: A total of 27 patients between 18 and 75 years old, divided by non-blinded fashion into a control group (15) and a clonidine group (12), were studied. All patients underwent identical technique of general anesthesia. Then, only the clonidine group received 1 μg kg−1 clonidine by spinal route. Levels of blood glucose, lactate and cortisol were measured at three consecutive times: T1, at the time of installation of invasive arterial pressure; T2, 10 min after the first dose for cardioplegia; and T3, at the time of skin suture; and troponin I values at T1 and T3. The variation of results between T2-T1, T3-T2, and T3-T1 was also evaluated. Results: There was a statistically significant difference only with respect to the variation in blood glucose in the clonidine group: T3-T2, p = 0.027 and T3-T1, p = 0.047. Conclusions: Spinal clonidine at a dose of 1 μg kg−1 did not decrease blood measurements of troponin, cortisol, or lactate. Blood glucose suffered a more moderate variation during the procedure in the clonidine group. This fact, already reported in the literature, requires further investigation to be clarified. .

Justificativa e objetivos: A intensa resposta ao trauma desencadeada pela circulação extracorpórea pode conduzir ao aumento da morbimortalidade. 0 presente estudo avaliou se a clonidina, fàrmaco da classe dos α-2 agonistas, por via raquidiana, sem associação com anestésicos locais ou opioides, reduz essa resposta em cirurgias cardíacas com uso de circulação extracorpórea. Método: Estudaram-se 27 pacientes entre 18 e 75 anos, separados de modo não encoberto em grupo controle (15) e grupo clonidina (12). Todos foram submetidos a técnica idéntica de anestesia geral. A seguir, apenas o grupo clonidina recebeu 1 mg.kg−1 de clonidina por via raquidiana. Foram dosados os valores de glicemia, lactato e cortisol em trés tempos consecutivos: T1, no momento da instalação da pressão arterial invasiva (PAM); T2, dez minutos após a primeira dose de cardioplegia; e T3 na sutura da pele, bem como os valores de troponina I em T1 e T3. Avaliou-se também a variação dos resultados entre: T2-T1; T3-T2 e T3-T1. Resultados: Houve diferença estatisticamente significativa apenas quanto à variação da glicemia no grupo clonidina: T3-T2 valor de p=0,027 e T3-T1 valor de p = 0,047. Conclusões: A clonidina espinhal em dose de 1 μg.kg−1 não diminuiu as dosagens sanguineas de troponina, cortisol ou lactato. A glicemia sofreu urna menor variação durante o procedimento no grupo clonidina. Esse fato, já registrado na literatura, necessita de maiores investigações para ser esclarecido. .

Introducción y objetivos: La intensa respuesta al trauma desencadenada por la circulación extracorpórea puede conducir al aumento de la morbimortalidad. El presente estudio eva-luó si la clonidina, fármaco de la clase de los α-2 agonistas, por vía raquídea, sin asociación con anestésicos locales u opiáceos, reduce esa respuesta en cirugías cardíacas con el uso de circulación extracorpórea. Método: Se estudiaron 27 pacientes entre 18 y 75 años, separados de modo no enmascarado en un grupo control (15) y un grupo clonidina (12). Todos fueron sometidos a la técnica idéntica de anestesia general. A continuación, solamente el grupo clonidina recibió 1 mgkg−1 de clonidina por vía raquídea. Se dosificaron los valores de glucemia, lactato y cortisol en 3 tiempos consecu-tivos: T1, al momento de la instalación de la presión arterial invasiva (PAP); T2, 10 min después de la primera dosis de cardioplejia; y T3 en la sutura de la piel, como también los valores de troponinai en T1 y T3. Evaluamos también la variación de los resultados entre T2-T1, T3-T2 y T3-T1. Resultados: Hubo una diferencia estadísticamente significativa solamente en cuanto a la variación de la glucemia en el grupo clonidina: T3-T2 valor de p = 0,027 y T3-T1 valor de p = 0,047. Conclusiones: La clonidina espinal en dosis de 1 μgkg−1 no disminuyó las dosificaciones sanguíneas de troponina, cortisol o lactato. La glucemia experimentó una menor variación durante el procedimiento en el grupo clonidina. Ese hecho, ya registrado en la literatura, necesita más investigaciones para ser clarificado. .

Effects of glutamine alone or in combination with zinc and vitamin A on growth, intestinal barrier function, stress and satiety-related hormones in Brazilian shantytown children

OBJECTIVE: To determine the impact of supplemental zinc, vitamin A, and glutamine alone or in combination on growth, intestinal barrier function, stress and satiety-related hormones among Brazilian shantytown children with low median height-for-age z-scores. METHODS: A randomized, double-blind, placebo-controlled trial was conducted in children aged two months to nine years from the urban shanty compound community of Fortaleza, Brazil. Demographic and anthropometric information was assessed. The random treatment groups available for testing (a total of 120 children) were as follows: (1) glutamine alone, n = 38; (2) glutamine plus vitamin A plus zinc, n = 37; and a placebo (zinc plus vitamin A vehicle) plus glycine (isonitrogenous to glutamine) control treatment, n = 38. Leptin, adiponectin, insulin-like growth factor (IGF-1), and plasma levels of cortisol were measured with immune-enzymatic assays; urinary lactulose/mannitol and serum amino acids were measured with high-performance liquid chromatography. ClinicalTrials.gov: NCT00133406. RESULTS: Glutamine treatment significantly improved weight-for-height z-scores compared to the placebo-glycine control treatment. Either glutamine alone or all nutrients combined prevented disruption of the intestinal barrier function, as measured by the percentage of lactulose urinary excretion and the lactulose:mannitol absorption ratio. Plasma leptin was negatively correlated with plasma glutamine (p = 0.002) and arginine (p = 0.001) levels at baseline. After glutamine treatment, leptin was correlated with weight-for-age (WAZ) and weight-for-height z-scores (WHZ) (p≤0.002) at a 4-month follow-up. In addition, glutamine and all combined nutrients (glutamine, vitamin A, and zinc) improved the intestinal barrier function in these children. CONCLUSION: Taken together, these findings reveal the benefits of glutamine alone or in combination ...

Estresse Isolado ou Associado ao Etanol Libera Prostanóides em Aorta de Ratos via ?2-Adrenoceptores / Stress Alone or associated with Ethanol Induces Prostanoid Release in Rat Aorta via ?2-Adrenoceptor

Fundamento: Estresse e etanol são ambos, independentemente, importantes fatores de risco cardiovascular. Objetivo: avaliar o risco cardiovascular do consumo de etanol e exposição ao estresse, isolados e em associação, em ratos machos adultos. Métodos: Os ratos foram separados em quatro grupos: controle, etanol (20% na água de beber durante seis semanas), estresse (imobilização 1h dia/5 dias por semana/ 6 semanas) e estresse/etanol. As curvas de concentração-resposta à noradrenalina - na ausência e na presença de ioimbina, L-NAME ou indometacina - ou fenilefrina foram determinadas em aortas torácicas com e sem endotélio. EC50 e resposta máxima (n = 8-12) foram comparadas através de ANOVA de dois fatores (two-way) / método de Bonferroni. Resultados: Estresse ou estresse em associação com o consumo de etanol aumentaram as respostas máximas de noradrenalina em aortas intactas. Essa hiper-reatividade foi eliminada pela remoção do endotélio, ou pela presença da indometacina ou ioimbina, mas não foi alterada pela presença de L-NAME. Enquanto isso, o consumo de etanol não alterou a reatividade à noradrenalina. As respostas da fenilefrina em aortas com e sem endotélio também permaneceram inalteradas independentemente do protocolo. Conclusão: O estresse crônico aumentou as respostas aórticas dos ratos à noradrenalina. Esse efeito é dependente do endotélio vascular e envolve a liberação de prostanóides vasoconstritores através da estimulação de α-2 adrenoceptores endoteliais. Além disso, o consumo crônico de etanol pareceu não influenciar as respostas de noradrenalina em aorta de rato, nem modificar o aumento de tais respostas observadas em consequência da exposição ao estresse. .

Background: Stress and ethanol are both, independently, important cardiovascular risk factors. Objective: To evaluate the cardiovascular risk of ethanol consumption and stress exposure, isolated and in association, in male adult rats. Methods: Rats were separated into 4 groups: Control, ethanol (20% in drinking water for 6 weeks), stress (immobilization 1h day/5 days a week for 6 weeks) and stress/ethanol. Concentration-responses curves to noradrenaline - in the absence and presence of yohimbine, L-NAME or indomethacin - or to phenylephrine were determined in thoracic aortas with and without endothelium. EC50 and maximum response (n=8-12) were compared using two-way ANOVA/Bonferroni method. Results: Either stress or stress in association with ethanol consumption increased the noradrenaline maximum responses in intact aortas. This hyper-reactivity was eliminated by endothelium removal or by the presence of either indomethacin or yohimbine, but was not altered by the presence of L-NAME. Meanwhile, ethanol consumption did not alter the reactivity to noradrenaline. The phenylephrine responses in aortas both with and without endothelium also remained unaffected regardless of protocol. Conclusion: Chronic stress increased rat aortic responses to noradrenaline. This effect is dependent upon the vascular endothelium and involves the release of vasoconstrictor prostanoids via stimulation of endothelial alpha-2 adrenoceptors. Moreover, chronic ethanol consumption appeared to neither influence noradrenaline responses in rat thoracic aorta, nor did it modify the increase of such responses observed as a consequence of stress exposure. .

Incorporation of Na+/H+ antiporter gene from Aeluropus littoralis confers salt tolerance in soybean (Glycine max L.).

To develop a salt-tolerant soybean (Glycine max L.) cultivar, a minimal linear Na+/H+ antiporter gene cassette (35S CaMV promoter, open-reading-frame of AlNHX1 from Aeluropus littoralis and NOS terminator) was successfully expressed in soybean cultivar TF-29. Southern and Northern blot analysis showed that AlNHX1 was successfully incorporated into the genome and expressed in the transgenic plants. The AlNHX1 transgenic plant lines exhibited improved growth in severe saline condition (150 mM NaCl). The transgenic lines accumulated a lower level of Na+ and a higher level of K+ in the leaves than wild-type plants under saline condition (150 mM NaCl). Observations on the chlorophyll content, photosynthetic rates, malondialdehyde and relative electrical conductivity indicated that transgenic plants exhibited tolerance to salt stress, growing normally at salt concentrations up to 150 mM. These results demonstrated that AlNHX1 was successfully transferred into soybean and the salt-tolerance was improved by the overexpression of AlNHX1.

Chronic stress enhances progression of periodontitis via alpha1-adrenergic signaling: a potential target for periodontal disease therapy

This study assessed the roles of chronic stress (CS) in the stimulation of the sympathetic nervous system and explored the underlying mechanisms of periodontitis. Using an animal model of periodontitis and CS, the expression of tyrosine hydroxylase (TH) and the protein levels of the alpha1-adrenergic receptor (alpha1-AR) and beta2-adrenergic receptor (beta2-AR) were assessed. Furthermore, human periodontal ligament fibroblasts (HPDLFs) were stimulated with lipopolysaccharide (LPS) to mimic the process of inflammation. The proliferation of the HPDLFs and the expression of alpha1-AR and beta2-AR were assessed. The inflammatory-related cytokines interleukin (IL)-1beta, IL-6 and IL-8 were detected after pretreatment with the alpha1/beta2-AR blockers phentolamine/propranolol, both in vitro and in vivo. Results show that periodontitis under CS conditions enhanced the expression of TH, alpha1-AR and beta2-AR. Phentolamine significantly reduced the inflammatory cytokine levels. Furthermore, we observed a marked decrease in HPDLF proliferation and the increased expression of alpha1-ARfollowing LPS pretreatment. Pretreatment with phentolamine dramatically ameliorated LPS-inhibited cell proliferation. In addition, the blocking of alpha1-ARsignaling also hindered the upregulation of the inflammatory-related cytokines IL-1beta, IL-6 and IL-8. These results suggest that CS can significantly enhance the pathological progression of periodontitis by an alpha1-adrenergic signaling-mediated inflammatory response. We have identified a potential therapeutic target for the treatment of periodontal disease, particularly in those patients suffering from concurrent CS.

Evaluation of changes in lipid peroxidation, ROS production, surface structures, secondary metabolites and yield of linseed (Linum usitatissimum L.) under individual and combined stress of ultraviolet-B and ozone using open top chambers.

The individual and interactive effects of supplemental UV-B (sUV-B) (ambient + 7.2 kJ m-2 d-1) and elevated O3 (ambient + 10 ppb) were evaluated under field conditions using open top chambers on two cultivars, Padmini and T-397 of linseed (Linum usitatissimum L.). Mean monthly surface level of O3 concentrations varied from 27.7 ppb to 59.0 ppb during the experimental period. Both UV-B and O3 induced the production of ROS (H2O2 and O2.-), resulting in significant damage of membranes due to lipid peroxidation and electrolyte leakage. Synthesis of secondary metabolites (flavonoids, anthocyanin, lignin and wax) was also enhanced in all the treatments, whereas biomass and yield were reduced. Alterations in frequency of stomata and wax distribution were also observed through scanning electron microscopy (SEM). Cultivar Padmini was found to be more sensitive because of higher damage of membrane vis-a-vis reduction in biomass and seed yield. However, concentrations of flavonoids, anthocyanin, lignin and wax were higher in T-397, suggesting its relative resistance against applied stress. Combined exposure of sUV-B and O3 was less harmful, as compared to their individual treatment. Among the three treatments, O3 was found to be more detrimental for overall growth and sUV-B for economic yield.

Effects of simultaneous exposure to stress and nicotine on nicotine-induced locomotor activation in adolescent and adult rats

Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although cross-sensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P) 28-37) and adult (P60-67) rats received nicotine (0.4 mg/kg, sc) or saline (0.9 percent NaCl, sc) and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc) or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats.

Plasmatic vasopressin in patients undergoing conventional infra-renal abdominal aorta aneurysm repair / Vasopressina plasmática em pacientes submetidos à correção de aneurisma de aorta infrarrenal

OBJECTIVES: To evaluate plasmatic arginine vasopressin (AVP) levels in patients undergoing scheduled conventional abdominal aortic aneurysm (AAA) repair. METHODS: Plasmatic AVP concentrations were measured by radioimmunoassay in 22 non-consecutive adult patients undergoing infra-renal AAA repair. They were under combined general and epidural anesthesia at the following time frames: 1 - pre-operative (T0); 2 - 2h (T1) and 6h (T2) after the surgical procedure; 3 - in the morning at the first (T3), second (T4) and third (T5) post-operative days. Some clinical and laboratory variables were also recorded. RESULTS: The mean age of patients was 68±10 years; 17 were males. Plasmatic AVP (mean±SD; pg/mL) was within the normal range at T0 (1.4±0.7; baseline), increasing significantly at T1 (62.6±62.9; P<0.001) and at T2 (31.5±49.7; P<0.001), with a progressive fall, returning to basal levels at T5 (2.1±3.8; P=NS). Positive and statistically significant correlations were found between AVP and glycemia, serum lactate and white blood cells counts, but not with systemic arterial pressure or plasma osmolarity during the postoperative period. CONCLUSIONS: Considering that no correlations were found between AVP levels and hemodynamic or plasmatic osmolarity variations in AAA repair, it seems that stress response is mainly secondary to noxious stimulation mediated by the autonomic nervous system that is not completely blocked by anesthetics.

OBJETIVOS: Avaliar os níveis plasmáticos de vasopressina (AVP) em pacientes submetidos à correção convencional de aneurisma de aorta abdominal (AAA). MÉTODOS: A AVP plasmática foi mensurada por radioimunoensaio em 22 pacientes não-consecutivos submetidos à correção eletiva de AAA infrarrenal sob anestesia geral + epidural nos seguintes momentos: pré-operatório (T0); 2h (T1) e 6h (T2) após a cirurgia; e nas manhãs do primeiro (T3), segundo (T4) e terceiro (T5) dia pós-operatório (PO). Variáveis clínicas e laboratoriais de interesse também foram anotadas. RESULTADOS: A média de idade dos pacientes foi de 68±10 anos, sendo 17 homens. A AVP plasmática (média±DP; pg/ mL) estava dentro de limites normais no T0 (1,4±0,7; basal), aumentando no T1 (62,6±62,9; P<0,001) e no T2 (31,5±49,7; P<0,001), e retornando aos valores basais no T5 (2,1±3,8; P=NS). Correlações positivas e significativas foram encontradas entre a AVP e glicemia, lactato sérico e leucócitos sanguíneos, mas não com a pressão arterial sistêmica ou com a osmolaridade plasmática no PO. CONCLUSÕES: Na cirurgia de reparação de AAA, considerando que nenhuma correlação foi encontrada entre os níveis de AVP e variações hemodinâmicas ou da osmolaridade plasmática, este achado sugere que a resposta ao estresse é predominantemente secundária aos estímulos dolorosos mediados pela parte autônoma do sistema nervoso, não completamente bloqueados pelos anestésicos.

Sublethal concentrations of waterborne copper induce cellular stress and cell death in zebrafish embryos and larvae

Copper is an essential ion that forms part of the active sites of many proteins. At the same time, an excess of this metal produces free radicals that are toxic for cells and organisms. Fish have been used extensively to study the effects of metals, including copper, present in food or the environment. It has been shown that different metals induce different adaptive responses in adult fish. However, until now, scant information has been available about the responses that are induced by waterborne copper during early life stages of fish. Here, acute toxicity tests and LC50 curves have been generated for zebrafish larvae exposed to dissolved copper sulphate at different concentrations and for different treatment times. We determined that the larvae incorporate and accumulate copper present in the medium in a concentration-dependent manner, resulting in changes in gene expression. Using a transgenic fish line that expresses enhanced green fluorescent protein (EGFP) under the hsp70 promoter, we monitored tissue-specific stress responses to waterborne copper by following expression of the reporter. Furthermore, TUNEL assays revealed which tissues are more susceptible to cell death after exposure to copper. Our results establish a framework for the analysis of whole-organism management of excess external copper in developing aquatic animals.

Endoplasmic reticulum stress (ER-stress) by 2-deoxy-D-glucose (2DG) reduces cyclooxygenase-2 (COX-2) expression and N-glycosylation and induces a loss of COX-2 activity via a Src kinase-dependent pathway in rabbit articular chondrocytes

Endoplasmic reticulum (ER) stress regulates a wide range of cellular responses including apoptosis, proliferation, inflammation, and differentiation in mammalian cells. In this study, we observed the role of 2-deoxy-D-glucose (2DG) on inflammation of chondrocytes. 2DG is well known as an inducer of ER stress, via inhibition of glycolysis and glycosylation. Treatment of 2DG in chondrocytes considerably induced ER stress in a dose- and time-dependent manner, which was demonstrated by a reduction of glucose regulated protein of 94 kDa (grp94), an ER stress-inducible protein, as determined by a Western blot analysis. In addition, induction of ER stress by 2DG led to the expression of COX-2 protein with an apparent molecular mass of 66-70kDa as compared with the normally expressed 72-74 kDa protein. The suppression of ER stress with salubrinal (Salub), a selective inhibitor of eif2-alpha dephosphorylation, successfully prevented grp94 induction and efficiently recovered 2DG-modified COX-2 molecular mass and COX-2 activity might be associated with COX-2 N-glycosylation. Also, treatment of 2DG increased phosphorylation of Src in chondrocytes. The inhibition of the Src signaling pathway with PP2 (Src tyrosine kinase inhibitor) suppressed grp94 expression and restored COX-2 expression, N-glycosylation, and PGE2 production, as determined by a Western blot analysis and PGE2 assay. Taken together, our results indicate that the ER stress induced by 2DG results in a decrease of the transcription level, the molecular mass, and the activity of COX-2 in rabbit articular chondrocytes via a Src kinase-dependent pathway.

Ascorbic acid protects against restraint stress-induced memory deficits in wistar rats

OBJECTIVE: Chronic stress has been shown to cause oxidative damage in the central nervous system. Although stress-induced impairments in learning and memory have been studied extensively, very few studies have investigated possible ways to prevent their ill effects. The present work was designed to study the protective effects of ascorbic acid in memory loss induced by chronic restraint stress. METHODS: Adult male Wistar rats were designated into the following groups: (i) Normal control, (ii) Ascorbic acid treatment, (iii) Vehicle control, (iv) Restraint stress, (v) Restraint stress + vehicle, and (vi) Restraint stress + ascorbic acid treatment. At the end of 21 days, animals of all groups were subjected to memory tests using Morris water maze and passive avoidance apparatus. Then, the results obtained were compared between the experimental groups. RESULTS: Rats exposed to restraint stress alone and those pretreated with vehicle solution before restrained stress showed deficits in learning and impaired memory retention in the memory tests when compared to animals in other experimental groups. Animals pretreated with ascorbic acid before restraining showed significant improvement in memory retention in the same memory tests. CONCLUSIONS: Results of this study suggest the possibility of using ascorbic acid as a dietary supplement to prevent stress-induced memory impairments.