Aluminium (Al) is toxic to most plants. Nevertheless, some species accumulate Al without showing toxicity symptoms. Previous studies have evidenced Al in chloroplasts of Al-accumulating species from the Cerrado vegetation in South America.
View Article and Find Full Text PDFThe first symptom of aluminum (Al) toxicity is the inhibition of root growth, which has been associated with low leaf hydration, with negative consequences for leaf gas exchange including stomatal conductance (gs) observed in many plant species. Here we asked whether low leaf hydration occurs before or after the inhibition of root growth of Citrus × limonia Osbeck ('Mandarin' lime) cultivated for 60 days in nutrient solution with 0 and 1480 μM Al. The length, diameter, surface area and biomass of roots of plants exposed to Al were lower than control plants only at 30 days after treatments (DAT).
View Article and Find Full Text PDFStyrax camporum Pohl. (Styracaceae) is a woody species that grows on acidic soils from the Brazilian savanna with high aluminum (Al) saturation (m% > 50%), where it accumulates ~ 1500 mg Al per kg dry leaves. Using nutrient solution, a previous study showed that 1480 μM Al causes toxicity symptoms, which raises the question whether less than 1480 μM Al could cause beneficial effects on this species.
View Article and Find Full Text PDFIn acidic soils, aluminium (Al) occurs as Al3+, which is phytotoxic. One of the most conspicuous symptoms of Al toxicity is the root growth inhibition, which can lead to low water uptake and consequent reduction in leaf hydration and gas exchange. However, fibrous xylem vessels have been observed in roots of 'Rangpur' lime plants (Citrus limonia L.
View Article and Find Full Text PDFCa -binding proteins are differentially expressed in the nervous system; their functional role often remains unclear. This immunohistochemical study aimed at characterising and comparing the expression pattern of the Ca -binding proteins calbindin (Calb), calretinin (Calr) and parvalbumin (Parv) in the retina of four species of macaque monkeys: Macaca fascicularis (cynomolgus macaque), M. mulatta (rhesus macaque), M.
View Article and Find Full Text PDFPrevious studies on the ultrastructure of the primate foveola suggested the presence of an inverted cone-like structure which is formed by 25-35 specialized Müller cells overlying the area of high photoreceptor density. We investigated the ultrastructure of the Müller cells in the foveola of a human and macaque retina. Sections through the posterior poles of an eye of a 40 years-old human donor and an eye of an adult cynomolgus monkey (Macaca fascicularis) were investigated with transmission electron microscopy.
View Article and Find Full Text PDFAn enhanced embryo-fetal development study was conducted in cynomolgus monkeys using pateclizumab, a humanized IgG1 monoclonal antibody (mAb) targeting lymphotoxin-alpha. Pateclizumab administration between gestation days (GD) 20 and 132 did not induce maternal or developmental toxicities. The ratio of fetal-to-maternal serum concentration of pateclizumab was 0.
View Article and Find Full Text PDFPremise Of The Study: Most bird-dispersed fruits are green when unripe and become colored and conspicuous when ripe, signaling that fruits are ready to be consumed and dispersed. The color pattern for fruits of Miconia albicans (Melastomataceae), however, is the opposite, with reddish unripe and green ripe fruits. We (1) verified the maintenance over time of its bicolored display, (2) tested the communicative function of unripe fruits, (3) tested the photoprotective role of anthocyanins in unripe fruits, and (4) verified whether green ripe fruits can assimilate carbon.
View Article and Find Full Text PDFDespite limitations of low fertility and high acidity of the soils, the cerrado flora is the richest amongst savannas. Many cerrado woody species show sclerophyllous leaves, which might be related to the availability of water and nutrients in the soil. To better understand the function and structure of cerrado vegetation within its own variations, we compared two cerrado communities: one in its core region in central Brazil (Brasília, DF) and the other on its southern periphery (Itirapina, SP).
View Article and Find Full Text PDFThe cerrado's flora comprises aluminum-(Al) accumulating and non-accumulating plants, which coexist on acidic and Al-rich soils with low fertility. Despite their existence, the ecological importance or biological strategies of these functional groups have been little explored. We evaluated the leaf flushing patterns of both groups throughout a year; leaf concentrations of N, P, K, Ca, Mg, S, Al, total flavonoids and polyphenols; as well as the specific leaf area (SLA) on young and mature leaves within and between the groups.
View Article and Find Full Text PDFWe developed linear equations to predict the leaf area (LA) of the species Styrax pohlii and Styrax ferrugineus using the width (W) and length (L) leaf dimensions. For both species the linear regression (Y=α+bX) using LA as a dependent variable vs. W × L as an independent variable was more efficient than linear regressions using L, W, L2 and W2 as independent variables.
View Article and Find Full Text PDFThe biomechanical properties of Müller glial cells may have importance in understanding the retinal tissue alterations after retinal surgery with removal of the inner limiting membrane and during the ontogenetic development, respectively. Here, we compared the viscoelastic properties of Müller cells from man and monkey as well as from different postnatal developmental stages of the rat. We determined the complex Young's modulus E = E' + iE″ in a defined range of deforming frequencies (30, 100, and 200 Hz) using a scanning force microscope, where the real part E' reflects the elastic property (energy storage or elastic stiffness) and the imaginary part E″ reflects the viscous property (energy dissipation) of the cells.
View Article and Find Full Text PDFTo understand the effect of summer and winter on the relationships between leaf carbohydrate and photosynthesis in citrus trees growing in subtropical conditions, 'Valencia' orange trees were subjected to external manipulation of their carbohydrate concentration by exposing them to darkness and evaluating the maximal photosynthetic capacity. In addition, the relationships between carbohydrate and photosynthesis in the citrus leaves were studied under natural conditions. Exposing the leaves to dark conditions decreased the carbohydrate concentration and increased photosynthesis in both seasons, which is in accordance with the current model of carbohydrate regulation.
View Article and Find Full Text PDFShoot and root lengths, the number of leaves, biomass and leaf area were measured in Styrax ferrugineus Nees and Mart., Styrax camporum Pohl. and Styrax pohlii A.
View Article and Find Full Text PDFA total of 33 tumors were observed during a time period of 15 years (1992-2006) in cynomolgus monkeys. The great majority of neoplasms was benign (23 benign neoplasms versus 10 malignant tumors). Fourteen appeared in males and 19 in females.
View Article and Find Full Text PDFBone Marrow Transplant
November 2007
Optimum storage conditions of cord blood-derived hematopoietic progenitor cells before isolation remain unknown. We therefore evaluated CD34+ cells isolated from cord blood units (n=57) within 1 h after collection and following storage for 24, 48 and 72 h at either room temperature (RT) or 4 degrees C. Isolated CD34+ cells were analyzed for their cell count, immunophenotype, apoptosis rate, clonogenicity and transmigration capacity in response to stroma-derived factor 1alpha using direct-paired comparisons (n=27).
View Article and Find Full Text PDFThymus development was studied in the cynomolgus monkey from day 35 of gestation (gd 35) to the stage of advanced involution in a 21-year-old monkey. Special emphasis was placed on thymus cell generation and cellular pattern formation. At gd 35, the epithelial bud of the thymus was visible in a sagittal position at the level of the thoracic aperture.
View Article and Find Full Text PDFNitric-oxide-sensitive guanylyl cyclase (NO-sGC) plays a pivotal role in many second messenger cascades. Neurotransmission- and neuropathology-related changes in NO-sGC have been suggested. However, the cellular localization of NO-sGC in primate brains, including humans, remains unknown.
View Article and Find Full Text PDFTwo hundred common marmosets (Callithrix jacchus) from control groups (100 males, 100 females) of toxicological studies were examined histopathologically to evaluate the spectrum of spontaneous lesions in this species. Frequent findings were extramedullary hematopoiesis affecting adrenal glands, liver, kidney and spleen, cystic Brunner's glands in the duodenum, acute or subacute inflammation in the large intestine and gall bladder, renal mineralization and pigmentation, hepatic Ito-cell vacuolation, microgranuloma and glycogen storage, pituitary cysts, C-cell hyperplasia and lymphocytic foci of the thyroid gland, luteal hyperplasia of the ovary and inflammatory cell foci in various organs.
View Article and Find Full Text PDFRetinae from rabbits and laboratory rodents are often used as 'models' of the human retina, although there are anatomical differences. To test whether monkey eyes provide a better model, a physiological study of Muller glial cells was performed comparing isolated cells and retinal wholemounts from the cynomolgus monkey, Macaca fascicularis and from man. The membrane conductance of Muller cells from both species was dominated by inward and outward K(+) currents.
View Article and Find Full Text PDFTwo epithelial plaques were observed in the uterus of a 4 years 8 month old non-pregnant cynomolgus monkey. Normally, epithelial plaques occur near the implantation site of primates during early pregnancy but can also be induced by various procedures. Both plaques consisted of clusters and nest of cells with large nuclei and a faintly basophilic cytoplasm.
View Article and Find Full Text PDFSquamous cysts and squamous epithelial plaques were observed in a total of seventeen cynomolgus monkeys. Eleven monkeys had squamous cysts, three of them also revealed squamous plaques and six revealed squamous plaques exclusively. At necropsy, cysts were recognized as yellow-white nodules with a smooth surface, that were located superficially along the interventricular septum, on the surface of the left ventricle or the apex of the heart.
View Article and Find Full Text PDFNonhuman primates are being used increasingly as a non-rodent animal model during preclinical toxicology and safety assessment on the basis of proven similarity and comparability between nonhuman primates and humans. The validity of the nonhuman primate models applies to many aspects of toxicological testing and holds particularly true for the evaluation of reproductive toxicology and developmental toxicology. More recently, the advent of humanized antibodies and vaccines imposed further demand on nonhuman primate models since many immunotherapeutics do not interact with rodent receptors but frequently only cross-react with primate tissue.
View Article and Find Full Text PDFExp Clin Endocrinol Diabetes
October 1997
The effects of systemic hypoxia upon cardiovascular and renal function in normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) are controversial. We examined the effects of systemic normobaric hypoxia (12.5% O2 in N2 for 4 hours) on arterial blood gases (pO2, pCO2, pH), mean arterial pressure (MAP), heart rate (HR), effective renal blood flow (ERBF), glomerular filtration rate (GFR), urine flow (UMV) and renal sodium excretion (U Na V) in conscious unilaterally nephrectomized WKY (n = 12) and SHR (n = 14) chronically instrumented with an arterial, venous and ureter cannula.
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