RESUMO
The flowers of the species of Malpighiaceae in the Neotropical Region are relatively uniform in their morphology due to their dependence on oil-collecting bees as their main pollinators. However, many species of the genus Galphimia seem to have acquired a different floral syndrome, lacking markedly zygomorphic flowers and developed elaiophores in the calyx. Likewise, these species present anthers with great development, probably in response to the selection of pollinators that collect pollen. Galphimia australis incorporated some of these traits but also retained some residual characteristics typical of species pollinated by oil bees. This leads to many questions on how these flowers ensure their pollination. Inquiring about the reduction or modification of these characteristics allows us to understand how G. australis achieves a different pollination syndrome. In this research, we carry out a detailed morphological and anatomical study of the flowers and pollen grain devolvement of G. australis and floral visitors were observed and captured. Results were analyzed in order to determine how this species changed from the oil-floral syndrome, typical of neotropical Malpighiaceae, to one syndrome with pollen as the main reward.
Assuntos
Galphimia , Malpighiaceae , Animais , Abelhas , Polinização/fisiologia , Malpighiaceae/fisiologia , Flores/anatomia & histologia , Pólen/fisiologiaRESUMO
This work describes the complete decontamination of three parcels of a dump site located in Lomas de Zamora county, Buenos Aires province (Argentina) heavily polluted with hexachorocyclohexane (HCH), where phytoremediation, successful in the surrounding areas, was ineffective. HCH contained in contaminated soil (10 g/kg average) was oxidized with sodium persulfate activated with citric acid chelated Fe(II). This chemical remediation process required treatment in situ in each parcel of approximately 10900 tons total of soil that were mechanically removed and initially mixed with 1750 tons of sodium persulfate. The mixture was then transferred to the excavation site, and 105 tons of ferrous sulfate and 35 tons of citric acid were finally added. The process, started in January 2011 and completed in February 2016, was very effective since chemical remediation average efficiency in the three parcels was higher than 99.99%. To the best of our knowledge this work is the first demonstration that persulfate oxidation activated with citric acid chelated Fe(II) can be successfully applied for field remediation of a relatively large area.
Assuntos
Recuperação e Remediação Ambiental , Poluentes do Solo , Hexaclorocicloexano , Argentina , Compostos Ferrosos , Oxirredução , Biodegradação Ambiental , Ácido Cítrico , Solo , Poluentes do Solo/análiseRESUMO
In 1996, a diagnostic study performed in a 16-ha field located in Buenos Aires Province (Argentina), where a chemical industry produced 1,2,3,4,5,6-hexachlorocyclohexane (HCH) from 1960 to 1978, showed contamination with HCH ranging from 10 to 20,000 mg kg-1 dry soil (706.4 mg kg-1 average). For remediation purposes, a forestation plan was put into practice in 1997 employing approximately 12,300 Eucalyptus dunnii seedlings which by 2016 where fully grown into trees that formed a forest where local fauna can be found. Midterm analysis done in 2005, when E. dunnii trees had developed into 8-10 m high trees, indicated that HCH was incorporated into leaves and logs and soil phytoremediation was progressing. Final quantitation analysis of HCH in soil performed in 2016 demonstrated that the 97.2% of the field area was effectively decontaminated with 98.1% overall average efficiency. Thus, this work is the first global example of a successful employment of E. dunnii trees for HCH phytoremediation purposes at field scale. These results may encourage other researchers to test the ability of E. dunnii to phytoremediate soils contaminated with other chlorinated compounds like polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs).
Assuntos
Benzofuranos/análise , Eucalyptus , Bifenilos Policlorados , Poluentes do Solo/análise , Argentina , Biodegradação Ambiental , Dibenzofuranos Policlorados , HexaclorocicloexanoRESUMO
The style morphology and anatomy vary among different species. Three basic types are: open, closed, and semi-closed. Cells involved in the pollen tube pathway in the different types of styles present abundant endoplasmic reticulum, dictyosomes, mitochondria, and ribosomes. These secretory characteristics are related to the secretion where pollen tube grows. This secretion can be represented by the substances either in the canal or in the intercellular matrix or in the cell wall. Most studies suggest that pollen tubes only grow through the secretion of the canal in open styles. However, some species present pollen tubes that penetrate the epithelial cells of the canal, or grow through the middle lamella between these cells and subepithelial cells. In species with a closed style, a pathway is provided by the presence of an extracellular matrix, or by the thickened cell walls of the stylar transmitting tissue. There are reports in some species where pollen tubes can also penetrate the transmitting tissue cells and continue their growth through the cell lumen. In this review, we define subtypes of styles according to the path of the pollen tube. Style types were mapped on an angiosperm phylogenetic tree following the maximum parsimony principle. In line with this, it could be hypothesized that: the open style appeared in the early divergent angiosperms; the closed type of style originated in Asparagales, Poales, and Eudicots; and the semi-closed style appeared in Rosids, Ericales, and Gentianales. The open style seems to have been lost in core Eudicots, with reversions in some Rosids and Asterids.
Assuntos
Flores/anatomia & histologia , Magnoliopsida/anatomia & histologia , Tubo Polínico/anatomia & histologia , Flores/fisiologia , Magnoliopsida/fisiologia , Tubo Polínico/fisiologiaRESUMO
Cabomba Aubl. is a genus that presents a range of features that have made it to be considered a potential genetic model for studies of early angiosperm evolution. Therefore, any study that expands our knowledge of this genus is potentially useful for the understanding of the evolution of early angiosperms. This paper reports the study of the anatomy and the ultrastructure of the stigma and the style of Cabomba caroliniana Gray during the 2 days of anthesis using bright-field microscope, fluorescence microscope and transmission electron microscope. The stigma is dry and has pluricellular papillae. The style is hollow with a central canal coated by an epithelium. The papillae have fewer organelles than those typical of glandular cells, and they are covered by a cuticle that is broken when pollen germinates. The ultrastructure of epithelial cells indicates that the cells lining the canal are secretory. The canal is filled with a fibrillar and granular substance. The pollen tubes grow inside the canal through this substance. The results are discussed in the context of what is known for other species of angiosperms.
Assuntos
Flores/ultraestrutura , Magnoliopsida/ultraestrutura , Epitélio/ultraestrutura , Flores/citologia , Germinação , Magnoliopsida/citologia , Tubo Polínico/citologia , Tubo Polínico/crescimento & desenvolvimento , Tubo Polínico/ultraestruturaRESUMO
Tapetum, orbicule, and pollen grain ontogeny in Colletia paradoxa and Discaria americana were studied with transmission electron microscopy (TEM). The ultrastructural changes observed during the different stages of development in the tapetal cells and related to orbicule and pollen grain formation are described. The proorbicules have the appearance of lipid globule, and their formation is related to the endoplasmic reticulum of rough type (ERr). This is the first report on the presence of orbicules in the family Rhamnaceae. Pollen grains are shed at the bicellular stage.
Assuntos
Pólen/fisiologia , Rhamnaceae/metabolismo , Citoplasma/metabolismo , Grão Comestível/metabolismo , Retículo Endoplasmático Rugoso/metabolismo , Gelatina/química , Glicerol/química , Lipídeos/química , Microscopia Eletrônica de Transmissão/métodos , Fenômenos Fisiológicos Vegetais , Pólen/química , Especificidade da EspécieRESUMO
For the first time in Argentina, we describe an outbreak of contact dermatitis. New pairs of shoes caused intense pruritus, pain, and eruption, followed by edema, blisters, and a severe negative impact on the epidermal barrier of the feet. We identify dimethylfumarate as the causal agent and suggest an analytical method for its fast identification.
Assuntos
Dermatite de Contato/etiologia , Pé/patologia , Fumaratos/efeitos adversos , Fungicidas Industriais/efeitos adversos , Adulto , Animais , Antibacterianos/uso terapêutico , Argentina , Vesícula/etiologia , Vesícula/patologia , Dermatite de Contato/patologia , Fumarato de Dimetilo , Epidemias , Eritema/patologia , Feminino , Fungicidas Industriais/uso terapêutico , Gentamicinas/uso terapêutico , Humanos , Hipersensibilidade/diagnóstico , Miconazol/uso terapêutico , Testes do Emplastro , Prurido/patologia , Coelhos , SapatosRESUMO
This is the first report of the ultrastructure of the stigma and style during and after anthesis in Helianthus annuus L. using light and transmission electron microscopy. The stigma is bifid with unicellular papillae. There is no secretion of lipids, carbohydrates or proteins at anthesis. The style is semisolid in the upper portion, closer to the stigma, and becomes solid below. Ultrastructural changes on cells of the stigma and the style are described. The transmitting tissue of the ovule is first evident 40 minutes after pollination and persists during the first stages of embryogenesis. Only one pollen tube per micropyle was observed growing through this tissue.
Assuntos
Flores/ultraestrutura , Helianthus/citologia , Helianthus/embriologia , Microscopia Eletrônica de Transmissão , Sementes/citologiaRESUMO
This is the first report of the ultrastructure of the stigma and style during and after anthesis in Helianthus annuus L. using light and transmission electron microscopy. The stigma is bifid with unicellular papillae. There is no secretion of lipids, carbohydrates or proteins at anthesis. The style is semisolid in the upper portion, closer to the stigma, and becomes solid below. Ultrastructural changes on cells of the stigma and the style are described. The transmitting tissue of the ovule is first evident 40 minutes after pollination and persists during the first stages of embryogenesis. Only one pollen tube per micropyle was observed growing through this tissue.(AU)
Assuntos
Flores/ultraestrutura , Helianthus/citologia , Helianthus/embriologia , Sementes/citologia , Microscopia Eletrônica de TransmissãoRESUMO
This is the first report of the ultrastructure of the stigma and style during and after anthesis in Helianthus annuus L. using light and transmission electron microscopy. The stigma is bifid with unicellular papillae. There is no secretion of lipids, carbohydrates or proteins at anthesis. The style is semisolid in the upper portion, closer to the stigma, and becomes solid below. Ultrastructural changes on cells of the stigma and the style are described. The transmitting tissue of the ovule is first evident 40 minutes after pollination and persists during the first stages of embryogenesis. Only one pollen tube per micropyle was observed growing through this tissue.
Assuntos
Flores/ultraestrutura , Helianthus/citologia , Helianthus/embriologia , Microscopia Eletrônica de Transmissão , Sementes/citologiaRESUMO
The iron compounds used for food fortification have to meet certain requisites related to their bioavailability, absorption mechanism, and toxicity, since they will be consumed by a massive population group. With these purposes, we evaluated a new product used for the iron fortification of milk and lacteous derivatives, called SFE-171, which is a ferrous sulfate, microencapsulated with phospholipids. The bioavailability studies were carried out using four groups of 30 female mice each. In two groups, we studied the absorption of ferrous ascorbate and ferrous sulfate, both in water as reference standards, which show absorptions of 13.1+/-4.9% and 13.2+/-4.3%, respectively. With the third group, we studied the absorption of ferrous sulfate in milk; its value, 7.9+/-3.2%, is significantly lower than that of the remaining groups, with a p < 0.01. The studies with SFE-171 in milk, were performed on the fourth group, with a result of 11.6+/-4.5%, demonstrating that its absorption does not differ significantly from that of the reference standards. The absorption mechanism was determined by means of in vivo self-displacement studies of the ferrous ion and the SFE-171, taking ferrous sulfate as the reference compound. For this study, 210 female mice were used, and no significant difference between the absorption mechanism of both products could be observed. Toxicity studies of the new product with regard to ferrous sulfate were carried out with two groups of 70 female mice each and two groups of 70 male mice each. The lethal dose 50% LD50 for SFE-171 and for ferrous sulfate was 1200 and 680 mg/kg for female mice and 1230 and 670 mg/kg for male mice, respectively, demonstrating that the toxicity of the first product is substantially lower than that of the reference standard. We conclude that the iron product under study has a high bioavailability, an absorption mechanism equal to that of nonhemic iron, and lower toxicity than ferrous sulfate.
Assuntos
Compostos Ferrosos/farmacocinética , Análise de Variância , Animais , Disponibilidade Biológica , Composição de Medicamentos , Feminino , Compostos Ferrosos/administração & dosagem , Compostos Ferrosos/toxicidade , Absorção Intestinal , Dose Letal Mediana , Masculino , CamundongosRESUMO
The behavior of SFE-171 used for food fortification was studied. The biological and nutritional properties of this new iron source are discussed in this work.
Assuntos
Laticínios/normas , Compostos Ferrosos/análise , Manipulação de Alimentos/métodos , Alimentos Fortificados/normas , Ferro da Dieta/administração & dosagem , Leite/normas , Adulto , Animais , Disponibilidade Biológica , Pré-Escolar , Laticínios/análise , Relação Dose-Resposta a Droga , Feminino , Compostos Ferrosos/metabolismo , Compostos Ferrosos/farmacocinética , Alimentos Fortificados/análise , Hematócrito , Humanos , Lactente , Ferro/análise , Ferro/sangue , Ferro/farmacocinética , Ferro da Dieta/metabolismo , Ferro da Dieta/farmacocinética , Masculino , Troca Materno-Fetal , Camundongos , Leite/química , Leite/metabolismo , Estado Nutricional , Gravidez , Fatores de Tempo , Água/análiseRESUMO
Iron deficiency is the most important nutritional problem all over the world. Fluid milk is an attractive vehicle for iron fortification, since it is a food with a high nutritional value, accessible to the whole population and easy to be given to children. Fortification of this food with iron has the disadvantage of the interaction of the iron with the constitutive elements of milk, diminishing its bioavailability and changing its sensorial properties, making it unacceptable. Nowadays, this problem can be overcome by the implementation of a new technological procedure, which consists in the microencapsulation of the ferrous sulfate with lecithin, thus avoiding the interaction of iron with the food. The absorption obtained in mice for milk-ferrous sulfate was 7.9 +/- 3.2%, while for microencapsulated ferrous sulfate-milk the result was 11.6 +/- 4.5%. Comparing these data with those obtained with the ferrous ascorbate in water 13.1 +/- 4.9% and ferrous sulfate in water 13.2 +/- 4.3%, both of them considered as reference standards, no statistically significant difference between them and the microencapsulated ferrous sulfate in milk can be observed. However, this difference becomes significant (p < 0.01) when these products are compared to the non-encapsulated ferrous sulfate in milk. On the other hand, we demonstrated that this product is stable to heat-processing (100 degrees C, 30 min) and storage at a room temperature up to 6 months that lacteous products are usually submitted to.
Assuntos
Compostos Ferrosos/química , Compostos Ferrosos/farmacocinética , Leite , Absorção , Animais , Ácido Ascórbico/farmacocinética , Disponibilidade Biológica , Composição de Medicamentos , Estabilidade de Medicamentos , Feminino , Temperatura Alta , Camundongos , Fosfatidilcolinas , Fatores de TempoRESUMO
Iron deficiency is one of the most important nutritional problems in the world. The best method to overcome this problem is the fortification of foods with highly bioavailable iron. Fluid milk is a massive consumption food with an easy access and which is generally the only food intake during the first months of life. Therefore the fortification of fluid milk with highly bioavailable iron and no detectable alterations of its sensorial characteristics was studied in the present work. This procedure was made possible using a new type of ferrous sulfate, stabilized and microencapsulated with soy lecitin (SFE-171). The iron concentration of the fortified milk is 12 mg per liter. In order to study the iron absorption from milk fortified with this product, SFE-171 was labeled with 59Fe and given to 29 volunteers with a normal iron status, each of which received an iron quantity of 3 mg in 250 ml of fluid milk. The average iron absorption was (10.2 +/- 4.7) %. This result shows that the iron given in this physicochemical form has the advantage of a high bioavailability and it is possible that this product will be the first attempt for an adequate solution of iron deficiency.
Assuntos
Compostos Ferrosos/farmacocinética , Ferro da Dieta/sangue , Leite Humano/química , Leite/química , Fenômenos Fisiológicos da Nutrição , Adulto , Anemia Ferropriva/prevenção & controle , Animais , Disponibilidade Biológica , Humanos , MasculinoRESUMO
It is known that the fortification of milk and its derivatives with iron has been recognized as a worldwide necessity, since the deficiency of this element produces different metabolic disorders. With this purpose, we have studied the iron absorption in mice after the administration of fluid milk and yogurt with FeSO4, stabilized by microencapsulation with soy lecithin (SFE-171) or with FeSO4, both labeled with 59Fe, which was used in the same experimental conditions for comparative purposes. The absorption of iron is influenced by the presence of some additives which usually are ingested together with milk, such as cacao, coffee, tea, "Argentine green herbs tea or maté" or cereals. The experimental results demonstrate that the iron absorption from SFE-171 is (12.3 +/- 2.9)%, whereas that from FeSO4 is (7.7 +/- 2.7)%, this difference is highly significant at p < 0.01. In all the cases, groups of 25 mice each were used to increase the statistical robustness of the experimental results. On the other hand, it could be demonstrated that the presence of 10% w/v cacao (Nesquik) increases the iron absorption in both cases, whereas 1% w/v cacao (Nesquik) and maté has no influence on the iron absorption if SFE-171 is used. Cereals (Nestum 3 cereals), yogurt and other additives like tea and coffee, for different reasons, decrease the absorption of this element.