Salt-tolerance mechanisms in quinoa: Is glycinebetaine the missing piece of the puzzle?

Salinization of arable land has been progressively increasing, which, along with the effects of climate change, poses a serious risk to food production. Quinoa is a halophyte species that grows and is productive in highly saline soils. This study addresses the mechanisms of response and adaptation to high salinity. We show that the differential distribution of sodium in plants depends on the variety, observing that varieties such as Pandela Rosada limit the passage transit of sodium to the aerial part of the plant, a mechanism that seems to be regulated by sodium transporters such as HKT1s or SOS1. Like other halophytes of the Amaranthaceae family, quinoa plants have salt glands (bladder cells), which have been reported to play an important role in salt tolerance. However, our study shows that the contribution of bladder glands to salt accumulation is rather low. The 1H-NMR metabolome study of quinoa subjected to salt stress showed important modifications in the contents of amino acids, sugars, organic acids, and quaternary ammonium compounds (glycinebetaine). The compound with a higher presence was glycinebetaine, which makes up 6% of the leaf dry matter under saline conditions. Our findings suggest that glycinebetaine can act as an osmolyte and/or osmoprotectant, facilitating plant development under high saline ambient.

Valoración del grado de resección de los macroadenomas hipofisarios en la resonancia magnética posquirúrgica inmediata / Assessment of the extent of pituitary macroadenomas resection in immediate postoperative MRI

Objetivo. Comprobar si es posible determinar el grado de resección de macroadenomas hipofisarios en la resonancia magnética (RM) hipofisaria posquirúrgica inmediata. Material y métodos. Se revisaron las RM hipofisarias de pacientes intervenidos desde enero de 2010 hasta octubre de 2014. Se incluyeron aquellos que tenían RM diagnóstica, RM posquirúrgica inmediata y al menos un control posterior. Se comprobó si los hallazgos entre la RM posquirúrgica inmediata y las RM posteriores eran concordantes. Se excluyeron los casos sin controles evolutivos y las reintervenciones por recidivas. El grado de resección tumoral lo dividimos en grupos: resección total, resección parcial y dudoso. Los estudios se realizaron en una máquina de 1.5 Tesla siguiendo el mismo protocolo de secuencias: una parte morfológica, otra dinámica con contraste intravenoso y otra con contraste tardío. Resultados. De 73 casos incluidos, la RM posquirúrgica inmediata se interpretó como resección total en 38 casos y resto tumoral en 28 casos, habiendo dudas en 7 casos. En los controles evolutivos se determinó resección total en 41 casos y resto tumoral en 32. Se obtuvo una sensibilidad para detección de restos tumorales de 0,71, una especificidad de 0,82, un valor predictivo positivo de 0,89 y un valor predictivo negativo de 0,85 en la RM posquirúrgica inmediata respecto a los controles evolutivos. Conclusión. La RM posquirúrgica inmediata de macroadenomas hipofisarios es útil para valorar el grado de resección tumoral y es un buen predictor del grado de resección real definitivo al comparar con las RM posteriores, permitiendo plantear el tratamiento adecuado de forma precoz (AU)

Objective. To evaluate if it is possible to determine the extent of pituitary macroadenomas resection in the immediate postoperative pituitary magnetic resonance imaging (MRI). Material and methods. MRI of patient with pituitary macroadenomas from January 2010 until October 2014 were reviewed. Those patients who had diagnostic MRI, immediate post-surgical MRI and at least one MRI control were included. We evaluate if the findings between the immediate postsurgical MRI and the subsequent MRI were concordant. Cases which didn’t have evolutionary controls and those who were reoperation for recurrence were excluded. The degree of tumor resection was divided into groups: total resection, partial resection and doubtful. All MRI studies were performed on a1.5T machine following the same protocol sequences for all cases. One morphological part, a dynamic contrast iv and late contrast part. Results. Of the 73 cases included, immediate postoperative pituitary MRI was interpreted as total resection in 38 cases and tumoral rest in 28 cases, uncertainty among rest or inflammatory changes in 7 cases. Follow- up MRI identified 41 cases total resection and tumoral rest in 32. Sensitivity and specificity of 0.78 and 0.82 and positive and negative predictive value (PPV and NPV) 0.89 and 0.89 respectively were calculated. Conclusion. Immediate post-surgery pituitary MRI is useful for assessing the degree of tumor resection and is a good predictor of the final degree of real resection compared with the following MRI studies. It allows us to decide the most appropriate treatment at an early stage (AU)

Assessment of the extent of pituitary macroadenomas resection in immediate postoperative MRI. / Valoración del grado de resección de los macroadenomas hipofisarios en la resonancia magnética posquirúrgica inmediata.

OBJECTIVE: To evaluate if it is possible to determine the extent of pituitary macroadenomas resection in the immediate postoperative pituitary magnetic resonance imaging (MRI). MATERIAL AND METHODS: MRI of patient with pituitary macroadenomas from January 2010 until October 2014 were reviewed. Those patients who had diagnostic MRI, immediate post-surgical MRI and at least one MRI control were included. We evaluate if the findings between the immediate postsurgical MRI and the subsequent MRI were concordant. Cases which didn't have evolutionary controls and those who were reoperation for recurrence were excluded. The degree of tumor resection was divided into groups: total resection, partial resection and doubtful. All MRI studies were performed on a1.5T machine following the same protocol sequences for all cases. One morphological part, a dynamic contrast iv and late contrast part. RESULTS: Of the 73 cases included, immediate postoperative pituitary MRI was interpreted as total resection in 38 cases and tumoral rest in 28 cases, uncertainty among rest or inflammatory changes in 7 cases. Follow- up MRI identified 41 cases total resection and tumoral rest in 32. Sensitivity and specificity of 0.78 and 0.82 and positive and negative predictive value (PPV and NPV) 0.89 and 0.89 respectively were calculated. CONCLUSION: Immediate post-surgery pituitary MRI is useful for assessing the degree of tumor resection and is a good predictor of the final degree of real resection compared with the following MRI studies. It allows us to decide the most appropriate treatment at an early stage.

Study of survival in patients with malignant lung lesions treated with radiofrequency

OBJECTIVE: To report on the survival of a series of patients with primary and metastatic lung tumours treated with radiofrequency (RF). Four years ago we published our preliminary experience with the use of this technique. MATERIALS AND METHODS: For a period of 8 years we have treated 59 patients (by means of a total of 70 procedures) with primary or metastatic pulmonary neoplastic lesions, which fulfilled inclusion criteria to perform the technique. They were in all cases non-surgical lesions that had been either previously treated or not. The technique was performed in the radiology suite, under conscious analgo-sedation. We treated primary pulmonary lesions, neoplastic recurrences, or metastases with curative or palliative intention (pain management). RESULTS: Current global survival rate is 19 patients (32 %) with a mean of 26.61 ± 3.17 months (range: 20.38 ± 32.83) and a median of 16.00 ± 3.57 (range: 8.99-23.00). If we establish the difference between primary and metastatic tumours, mean survival is 27.62 ± 4.12 months in primary tumours (median: 16.00) vs. 24.65 ± 4.47 months in metastatic tumours (median: 16.00). When we studied the survival in those cases with a curative intent, mean survival in primary tumours was 30.97 ± 4.57 months (median: 21.00) vs. 25.14 ± 4.68 (median: 16.00) months in metastatic tumours. CONCLUSIONS: RF ablation of lung lesions is a minimally invasive procedure that is useful in primary tumours (especially in stage I) and metastatic ones. RF has proven its usefulness in the multidisciplinary treatment of this pathology due to the low incidence of serious complications and survival obtained, considering that patients are elderly with significant comorbidity (AU)

Carnosol, radiation and melanoma: a translational possibility

PURPOSE: To compare the genoprotective and radioprotective effect of carnosol (COL) against damage induced by ionizing radiation with similar effects produced by different antioxidant compounds. METHODS: The genoprotective effect was studied by means of the micronucleus test for antimutagenic activity in which the reduction in the frequency of micronuclei was evaluated in cytokinesis-blocked cells of human lymphocytes. The radioprotective effects were studied by cell viability test (MTT) in PNT2 (normal prostate) and B16F10 (melanoma) cell lines when they were administered before exposure to different X-ray doses (4, 6, 8, 10 and 0 Gy). RESULTS: Carnosol shows a significant genoprotective capacity (p < 0.001) against radiation with a protection factor of 50 %, and a dose-reduction factor of 4.3. Cell survival obtained with COL administered before exposure to 10 Gy of X-rays showed a protection factor of 55.1 %, eliminating 39 % of radiation-induced cell death in normal epithelial cells of prostate (PNT2) (p < 0.001). However, in the melanoma cell lines (B16F10) assayed, COL acted not as a radioprotector, but as a sensitizing agent increasing the cellular death by 34 % (p < 0.01) and producing an enhancement ratio of 2.12. CONCLUSIONS: Carnosol may be developed as a radioprotective agent in the non-tumoral cells. However, in the B10F16 melanoma cells, melanogenesis is activated by COL leading to redistribution of the enzymatic balances of glutathione and cysteine-lyase production, which could compromise the intracellular redox defence system. This effect appears as an increase in the capacity of ionizing radiation-induced damage, and thus exhibits a paradoxical protective effect of COL on melanoma cells (AU)

Study of survival in patients with malignant lung lesions treated with radiofrequency.

OBJECTIVE: To report on the survival of a series of patients with primary and metastatic lung tumours treated with radiofrequency (RF). Four years ago we published our preliminary experience with the use of this technique. MATERIALS AND METHODS: For a period of 8 years we have treated 59 patients (by means of a total of 70 procedures) with primary or metastatic pulmonary neoplastic lesions, which fulfilled inclusion criteria to perform the technique. They were in all cases non-surgical lesions that had been either previously treated or not. The technique was performed in the radiology suite, under conscious analgo-sedation. We treated primary pulmonary lesions, neoplastic recurrences, or metastases with curative or palliative intention (pain management). RESULTS: Current global survival rate is 19 patients (32 %) with a mean of 26.61 ± 3.17 months (range: 20.38 ± 32.83) and a median of 16.00 ± 3.57 (range: 8.99-23.00). If we establish the difference between primary and metastatic tumours, mean survival is 27.62 ± 4.12 months in primary tumours (median: 16.00) vs. 24.65 ± 4.47 months in metastatic tumours (median: 16.00). When we studied the survival in those cases with a curative intent, mean survival in primary tumours was 30.97 ± 4.57 months (median: 21.00) vs. 25.14 ± 4.68 (median: 16.00) months in metastatic tumours. CONCLUSIONS: RF ablation of lung lesions is a minimally invasive procedure that is useful in primary tumours (especially in stage I) and metastatic ones. RF has proven its usefulness in the multidisciplinary treatment of this pathology due to the low incidence of serious complications and survival obtained, considering that patients are elderly with significant comorbidity.

Carnosol, radiation and melanoma: a translational possibility.

PURPOSE: To compare the genoprotective and radioprotective effect of carnosol (COL) against damage induced by ionizing radiation with similar effects produced by different antioxidant compounds. METHODS: The genoprotective effect was studied by means of the micronucleus test for antimutagenic activity in which the reduction in the frequency of micronuclei was evaluated in cytokinesis-blocked cells of human lymphocytes. The radioprotective effects were studied by cell viability test (MTT) in PNT2 (normal prostate) and B16F10 (melanoma) cell lines when they were administered before exposure to different X-ray doses (4, 6, 8, 10 and 0 Gy). RESULTS: Carnosol shows a significant genoprotective capacity (p < 0.001) against radiation with a protection factor of 50 %, and a dose-reduction factor of 4.3. Cell survival obtained with COL administered before exposure to 10 Gy of X-rays showed a protection factor of 55.1 %, eliminating 39 % of radiation-induced cell death in normal epithelial cells of prostate (PNT2) (p < 0.001). However, in the melanoma cell lines (B16F10) assayed, COL acted not as a radioprotector, but as a sensitizing agent increasing the cellular death by 34 % (p < 0.01) and producing an enhancement ratio of 2.12. CONCLUSIONS: Carnosol may be developed as a radioprotective agent in the non-tumoral cells. However, in the B10F16 melanoma cells, melanogenesis is activated by COL leading to redistribution of the enzymatic balances of glutathione and cysteine-lyase production, which could compromise the intracellular redox defence system. This effect appears as an increase in the capacity of ionizing radiation-induced damage, and thus exhibits a paradoxical protective effect of COL on melanoma cells.

Effects of bioreactor hydrodynamics on the physiology of Streptomyces.

Streptomyces are filamentous bacteria which are widely used industrially for the production of therapeutic biomolecules, especially antibiotics. Bioreactor operating conditions may impact the physiological response of Streptomyces especially agitation and aeration as they influence hydromechanical stress, oxygen and nutrient transfer. The understanding of the coupling between physiological response and bioreactor hydrodynamics lies on a simultaneous description of the flow and transfers encountered by the bacteria and of the microbial response in terms of growth, consumption, morphology, production or intracellular signals. This article reviews the experimental and numerical works dedicated to the study of the coupling between bioreactor hydrodynamics and antibiotics producing Streptomyces. In a first part, the description of hydrodynamics used in these works is presented and then the main relations used. In a second part, the assumptions made in these works are discussed and put into emphasize. Lastly, the various Streptomyces physiological responses observed are detailed and compared.

Potassium starvation induces oxidative stress in Solanum lycopersicum L. roots.

The relationship between potassium deficiency and the antioxidative defense system has received little study. The aim of this work was to study the induction of oxidative stress in response to K(+) deficiency and the putative role of antioxidants. The tomato plants were grown in hydroponic systems to determine the role of reactive oxygen species (ROS) in the root response to potassium deprivation. Parameters of oxidative stress (malondialdehyde and hydrogen peroxide (H(2)O(2)) concentration), activities of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and glutathione reductase (GR)) and antioxidant molecules (ascorbate (ASC) and glutathione) were investigated. H(2)O(2) was subcellularly located by laser confocal microscopy after potassium starvation in roots. During the first 24h, H(2)O(2) induced the cascade of the cellular response to low potassium, and ROS accumulation was located mainly in epidermal cells in the elongation zone and meristematic cells of the root tip and the epidermal cells of the mature zones of potassium starved roots. The activity of the antioxidative enzymes SOD, peroxidase and APX in potassium deprivation significantly increased, whereas CAT and DHAR activity was significantly depressed in the potassium starvation treatment compared to controls. GR did not show significant differences between control and potassium starvation treatments. Based on these results, we put forward the hypothesis that antioxidant molecule accumulations probably scavenge H(2)O(2) and might be regenerated by the ASC-glutathione cycle enzymes, such as DHAR and GR.

Oxygen supply controls the onset of pristinamycins production by Streptomyces pristinaespiralis in shaking flasks.

Antibiotics are secondary metabolites, generally produced during stationary phase of growth under different nutritional and hydrodynamic stresses. However, the exact mechanisms of the induction of antibiotics production are still not clearly established. In a previous study, the induction of pristinamycins production by Streptomyces pristinaespiralis as well as product concentrations were correlated with power dissipation per unit of volume (P/V) in shaking flasks. In this study, detailed kinetics of growth, substrate consumption, oxygen transfer rate and pristinamycins production under varying P/V conditions have been obtained and analyzed. Our results showed that higher P/V resulted in a higher concentration of biomass and promoted an earlier nutrient limitation and ultimately an earlier induction of pristinamycins production. The maximal specific growth rate, specific oxygen consumption rate and specific consumption rate of glutamate increased with P/V while influence was less marked with specific consumption rate of glucose, arginine, ammonium ions and phosphate. When oxygen uptake rate (OUR) was limited by free-surface oxygen transfer, pristinamycins production was not detected despite the occurrence of nitrogen and/or phosphate sources limitation. The threshold value for OUR observed was around 25 mmol L(-1) h(-1). This suggested that a limitation in nitrogen and/or phosphate alone was not sufficient to induce pristinamycins production by S. pristinaespiralis pr11. To induce this production, the oxygen transfer had to be non-limiting.

Changes to the proteome and targeted metabolites of xylem sap in Brassica oleracea in response to salt stress.

Root-to-shoot signalling via xylem sap is an important mechanism by which plants respond to stress. This signalling could be mediated by alteration in the concentrations of inorganic and/or organic molecules. The effect of salt stress on the contents of xylem sap in Brassica olarecea has been analysed by mass spectrometry in order to quantify these changes. Subcellular location of arabinogalactan proteins (AGPs) by immunogold labelling and peroxidase isozymes was also analysed by isoelectrofocusing. The xylem sap metabolome analysis demonstrated the presence of many organic compounds such as sugars, organic acids and amino acids. Of these, amino acid concentrations, particularly that of glutamine, the major amino acid in the sap, were substantially reduced by salt stress. The xylem sap proteome analysis demonstrated the accumulation of enzymes involved in xylem differentiation and lignification, such as cystein proteinases, acid peroxidases, and a putative hydroxycinnamoyl-CoA:shikimate hydroxycinnamoyl transferase under salt stress. The peroxidase isozyme pattern showed that salt stress induced a high accumulation of an acid isoform. These results suggest that xylem differentiation and lignification is induced by salt stress. The combination of different methods to analyse the xylem sap composition provides new insights into mechanisms in plant development and signalling under salt stress.

Characterisation and changes in the antioxidant system of chloroplasts and chromoplasts isolated from green and mature pepper fruits.

Purification and characterisation of pepper (Capsicum annuum L) chloroplasts and chromoplasts isolated from commercial green, red and yellow mature fruits were undertaken. Induction of the synthesis of several antioxidants in organelles isolated from mature fruits was found. The ultrastructure of organelles and the presence and activity of SOD isozymes and enzymes involved in the ASC-GSH cycle, together with the non-enzymatic antioxidant content and some oxidative parameters, were analysed. It was found that lipids, rather than proteins, seem to be a target for oxidation in the chromoplasts. The ascorbate and glutathione contents were elicited during differentiation of chloroplasts into chromoplasts in both red and yellow fruits. The activity of SOD and of components of the ASC-GSH cycle was up-regulated, suggesting that these enzymes may play a role in the protection of plastids and could act as modulators of signal molecules such as O(2) ( -) and H(2)O(2) during fruit maturation. The presence of an Mn-SOD in chromoplasts isolated from yellow pepper fruits was also investigated in terms of structural and antioxidant differences between the two cultivars.

Role of phi cells and the endodermis under salt stress in Brassica oleracea.

Phi cell layers were discovered in the 19th century in a small number of species, including members of the Brassicaceae family. A mechanical role was first suggested for this structure; however, this has never been demonstrated. The main objective of the present work was to analyse the ultrastructure of phi cells, their influence on ion movement from the cortex to the stele, and their contribution to salt stress tolerance in Brassica oleracea. Transmission electron microscopy and X-ray microanalysis studies were used to analyse the subcellular structure and distribution of ions in phi cells and the endodermis under salt stress. Ion movement was analysed using lanthanum as an apoplastic tracer. The ultrastructural results confirm that phi cells are specialized cells showing cell wall ingrowths in the inner tangential cell walls. X-ray microanalysis confirmed a build-up of sodium. Phi thickenings were lignified and lanthanum moved periplasmically at this level. To the best of our knowledge, this is the first study reporting the possible role of the phi cells as a barrier controlling the movement of ions from the cortex to the stele. Therefore, the phi cell layer and endodermis seem to be regulating ion transport in Brassica oleracea under salt stress.

Asociación de angiomas cavernosos con venosos / Association of cavernous and venous angiomas

Introducción. Los angiomas cavernosos y venosos deforma aislada son malformaciones vasculocerebrales frecuentes.Su asociación se identifica cada vez más debido ala mayor utilización de la resonancia magnética (RM) en losestudios cerebrales. Objetivo. Analizar las características de la asociaciónentre angioma cavernoso y venoso y la relación con su localizacióny tamaño, el sexo del paciente y el uso de contrasteintravenoso para el diagnóstico por RM. Métodos. Retrospectivamente se han revisado los estudiosde RM cerebral de 37 pacientes con angiomas cavernosos.Las relaciones estadísticas se establecieron con tablas decontingencia y el estadístico de la χ2 de Pearson y la t deStudent para muestras independientes. Resultados. Se identificaron 52 angiomas cavernososen 37 pacientes. No se han encontrado diferencias estadísticamentesignificativas que relacionen el tamaño del angiomacavernoso, su localización y el sexo del paciente con laexistencia de un angioma venoso asociado. Sólo la administraciónde contraste ha mostrado una relación estadísticamentesignificativa para su diagnóstico. Conclusiones. La asociación de angioma cavernoso y venosoes frecuente (30 %). Es necesario administrar contrastepara detectar los angiomas venosos. Esta asociación tiene implicacionespronósticas por el riesgo de sangrado y quirúrgicas,ya que la resección de la anomalía venosa no se aconsejapor la posibilidad de desencadenar infartos venosos

Introduction. Isolated cavernous and venous angiomasare common vascular cerebral malformations. Due to theroutine use of magnetic resonance imaging (MRI) in cerebral studies, their association has been identified more frequently. Objective. To analyze the characteristics of the association between both lesions (cavernous and venous angiomas), and the relationships with localization, size, patient gender and the use of intravenous contrast material in the diagnosis with MR.Methods. A retrospective analysis of the cerebral MRIstudies of 37 patients with cavernous angiomas was made.Statistical relationships were established with contingency tables and statistical methods of Pearson χ2 and of Student’s test for independent samples. Results. A total of 52 cavernous angiomas were identified in 37 patients. No significant statistical differenceswere found that related the cavernous angioma size, localization or patient gender with the existence ofan associated venous angioma. Only the administrationof contrast material has shown a statistically significantrelationship for the diagnosis. Conclusions. The association of cavernous and venous angioma is frequent (30 %). Contrast material must be administeredto detect venous angiomas. This association hasprognostic implications, due to bleeding risk and surgerysince resection of the venous anomaly is not recommendeddue to the possible venous infarction

[Association of cavernous and venous angiomas]. / Asociación de angiomas cavernosos con venosos.

INTRODUCTION: Isolated cavernous and venous angiomas are common vascular cerebral malformations. The routine use of magnetic resonance imaging (MRI) in cerebral studies has shown their frequent association. OBJECTIVE: An analysis of the association characteristics of both lesions (cavernous and venous angiomas), and the relationships with localization, size, patient sex and the use of intravenous contrast material in the diagnosis with MR. METHODS: A retrospective analysis of the cerebral MRI studies of 37 patients with cavernous angiomas. Statistical relations were established with contingency tables and statistical methods of Pearson c2 and t of Student for independent samples. Results. 52 cavernous angiomas were identified in the 37 patients. No significant statistical differences were found that related the cavernous angioma size, localization or patient sex with the existence of an associated venous angioma. Only the administration of contrast material has shown a statistical significance for the diagnosis. CONCLUSIONS: The association of cavernous and venous angioma is frequent (30%). This association has prognostic implications, due to bleeding risk, and surgical as it is not recommended the resection of the venous anomaly due to the possible venous infarction. To detect venous angiomas is necessary the administration of contrast material.

Subcellular effects of drought stress in Rosmarinus officinalis.

The use of Rosmarinus officinalis, and other wild plant species, in the Mediterranean area is an interesting solution in order to avoid the desertification and rapid soil erosion, because of their good resistance to environmental conditions. Previous articles have described experiments designed to determine the impact of water stress at the plant level in this species, but more knowledge is required at the subcellular and ultrastructural levels. An anatomic and ultrastructural study of the leaves was conducted on Rosmarinus officinalis plants growing under different water treatments. In the leaves of water-stressed plants, the leaf water potential and turgor decreased, and leaf osmotic potential became more negative with respect to control plants. The anatomic investigations showed that both the mesophyll intercellular spaces and the epidermal cell size were reduced significantly under the more intense drought stress conditions. At the subcellular level, chloroplasts accumulated plastoglobuli and lipid bodies, and cuticle thickness was increased under water stress. In our experiment, the anatomic and ultrastructural modifications of Rosmarinus officinalis could be considered an additional adaptation to drought stress together with physiological and biochemical modifications as antioxidant accumulation.

Modulation of plant morphology, root architecture, and cell structure by low vitamin C in Arabidopsis thaliana.

Ascorbic acid (AA) fulfils many essential functions in plants. It is a key antioxidant and an important reducing substrate for a number of enzymes. The effects of low AA on plant architecture and leaf ultrastructure were studied in Arabidopsis thaliana mutants, which have constitutively moderately low (vtc1) or very low (vtc2) leaf AA contents compared with the wild type. Shoot development was comparable in all accessions over the first 14 d of growth. The production of primary roots was slightly different in vtc1, vtc2, and wild-type plants. However, the most notable difference was that a high proportion of the primary roots of the vtc2 plants grown on soil had lost the wild-type responses to gravity. The vtc mutants showed the antagonistic interaction between nitrate and sugar in the regulation of lateral root (LR) development that was observed in the wild type. However, the vtc2 mutants produced greater numbers of longer LRs than wild-type or vtc1 plants at all levels of nitrate. At later stages of development, the vtc rosettes were smaller than those of the wild type and the leaves showed intracellular structural changes that are consistent with programmed cell death (PCD). PCD symptoms such as nuclear chromatin condensation, the presence of multivesicular bodies, and extensive degradation and disorganization of the grana stacks were observed in 8-week-old vtc2 leaves and in 10-week-old vtc1 leaves. The data presented here illustrate the importance of tissue AA contents in regulating whole plant morphology, cell structure, and development.

Specification of adaxial and abaxial stomata, epidermal structure and photosynthesis to CO2 enrichment in maize leaves.

Acclimation to CO2 enrichment was studied in maize plants grown to maturity in either 350 or 700 microl l-1 CO2. Plants grown with CO2 enrichment were significantly taller than those grown at 350 microl l-1 CO2 but they had the same number of leaves. High CO2 concentration led to a marked decrease in whole leaf chlorophyll and protein. The ratio of stomata on the adaxial and abaxial leaf surfaces was similar in all growth conditions, but the stomatal index was considerably increased in plants grown at 700 microl l-1 CO2. Doubling the atmospheric CO2 content altered epidermal cell size leading to fewer, much larger cells on both leaf surfaces. The photosynthesis and transpiration rates were always higher on the abaxial surface than the adaxial surface. CO2 uptake rates increased as atmospheric CO2 was increased up to the growth concentrations on both leaf surfaces. Above these values, CO2 uptake on the abaxial surface was either stable or increased as CO2 concentration increased. In marked contrast, CO2 uptake rates on the adaxial surface were progressively inhibited at concentrations above the growth CO2 value, whether light was supplied directly to this or the abaxial surface. These results show that maize leaves adjust their stomatal densities through changes in epidermal cell numbers rather than stomatal numbers. Moreover, the CO2-response curve of photosynthesis on the adaxial surface is specifically determined by growth CO2 abundance and tracks transpiration. Conversely, photosynthesis on the abaxial surface is largely independent of CO2 concentration and rather independent of stomatal function.

Electron beam ionization induced oxidative enzymatic activities in pepper (Capsicum annuum L.), associated with ultrastructure cellular damages.

Mature green pepper fruits (Capsicum annuum L.) were subjected to ionizing radiation, in the range of 1-7 kGy, with accelerated electrons. Ultrastructural changes by electron microscopy, and the activity of several oxidative metabolism-related enzymes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), guaicol peroxidase (POX), and lipoxygenase (LOX), were determined in pericarp tissue just after the ionization treatment and during postionization storage at 7 degrees C followed by 3 days at 20 degrees C. Changes in oxidative stress during the ionization treatment was assessed by the accumulation of malondyaldehide (MDA), a lipid peroxidation product. The ionization induced modifications in the cell ultrastructure, a moderate separation of the plasma membrane from the cell wall being observed for all doses. At 5 and 7 kGy, peroxisomes were not detected and the structures of the chloroplast and vacuoles were seriously damaged. Lipid peroxidation and lipoxygenase activity increased with the ionization dose, staying constant and decreasing, respectively, during the storage period. Conversely, catalase, ascorbate peroxidase, and superoxide dismutase had lower values than in nonionized fruits and, in general, their values did not change or diminished slightly from the seventh day of storage. Peroxidase exhibited an increase in activity with the ionization dose, although these was not a linear relationship, with higher values at 3kGy. Ionization of pepper, especially at doses of 5 and 7 kGy, caused a significant oxidative damage in the fruit, since it increased oxidation and decreased the antioxidant enzymatic defense systems causing ultrastructural changes at cell level.

Characterization of the novel ophthalmic drug carrier Sophisen in two of its derivatives: 3A Ofteno and Modusik-A Ofteno.

Sophisen, a new ophthalmic drug carrier, was characterized using physicochemical and morphological criteria. Diclofenac belongs to a nonsteroidal anti-inflammatory molecule group and its ophthalmic use avoids side effects produced by steroid drugs. Cyclosporine-A is a cyclic peptide used as an immunosuppressive when administrated systemically. Its application in ophthalmology has been reported, but it is a very poor soluble drug. Diclofenac sodium and Cyclosporine-A were mixed with Sophisen to render two new ophthalmic solutions that were named 3A Ofteno and Modusik-A Ofteno, respectively. Based on transmission electron microscopy and dynamic light scattering studies, we concluded that Sophisen is a polydisperse solution with a molecular weight of 413 +/-122 kDa, whereas 3A Ofteno and Modusik-A Ofteno are monodisperse solutions with molecular weights of 169 +/- 44 and 153 +/- 10, respectively. Sophisen was shown to be a good carrier for diclofenac sodium as evaluated by passive diffusion through the cornea. A comparative study suggests that diclofenac applied as eye drops was better tolerated when associated with Sophisen. In addition, Modusik-A Ofteno, a new aqueous solution of Cyclosporine-A, improved tear production in patients with moderate or severe dry eye condition.