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91.
Patrizia Trifil�� Fabio Raimondo Maria Assunta Lo Gullo Andrea Nardini Sebastiano Salleo 《Annals of botany》2010,106(2):333-341
Background and Aims
The hydraulic architecture and water relations of fruits and leaves of Capsicum frutescens were measured before and during the fruiting phase in order to estimate the eventual impact of xylem cavitation and embolism on the hydraulic isolation of fruits and leaves before maturation/abscission.Methods
Measurements were performed at three different growth stages: (1) actively growing plants with some flowers before anthesis (GS1), (2) plants with about 50 % fully expanded leaves and immature fruits (GS2) and (3) plants with mature fruits and senescing basal leaves (GS3). Leaf conductance to water vapour as well as leaf and fruit water potential were measured. Hydraulic measurements were made using both the high-pressure flow meter (HPFM) and the vacuum chamber (VC) technique.Key Results
The hydraulic architecture of hot pepper plants during the fruiting phase was clearly addressed to favour water supply to growing fruits. Hydraulic measurements revealed that leaves of GS1 plants as well as leaves and fruit peduncles of GS2 plants were free from significant xylem embolism. Substantial increases in leaf petiole and fruit peduncle resistivity were recorded in GS3 plants irrespective of the hydraulic technique used. The higher fraction of resistivity measured using the VC technique compared with the HPFM technique was apparently due to conduit embolism.Conclusions
The present study is the first to look at the hydraulics of leaves and fruits during growth and maturation through direct, simultaneous measurements of water status and xylem efficiency of both plant regions at different hours of the day. 相似文献92.
93.
Maud Hertzog Francesca Milanesi Larnele Hazelwood Andrea Disanza HongJun Liu Emilie Perlade Maria Grazia Malabarba Sebastiano Pasqualato Alessio Maiolica Stefano Confalonieri Christophe Le Clainche Nina Offenhauser Jennifer Block Klemens Rottner Pier Paolo Di Fiore Marie-France Carlier Niels Volkmann Dorit Hanein Giorgio Scita 《PLoS biology》2010,8(6)
Actin capping and cross-linking proteins regulate the dynamics and architectures
of different cellular protrusions. Eps8 is the founding member of a unique
family of capping proteins capable of side-binding and bundling actin filaments.
However, the structural basis through which Eps8 exerts these functions remains
elusive. Here, we combined biochemical, molecular, and genetic approaches with
electron microscopy and image analysis to dissect the molecular mechanism
responsible for the distinct activities of Eps8. We propose that bundling
activity of Eps8 is mainly mediated by a compact four helix bundle, which is
contacting three actin subunits along the filament. The capping activity is
mainly mediated by a amphipathic helix that binds within the hydrophobic pocket
at the barbed ends of actin blocking further addition of actin monomers.
Single-point mutagenesis validated these modes of binding, permitting us to
dissect Eps8 capping from bundling activity in vitro. We further showed that the
capping and bundling activities of Eps8 can be fully dissected in vivo,
demonstrating the physiological relevance of the identified Eps8
structural/functional modules. Eps8 controls actin-based motility through its
capping activity, while, as a bundler, is essential for proper intestinal
morphogenesis of developing Caenorhabditis elegans. 相似文献
94.
Cesare de Gregorio Lorenzo Curtò Antonino Recupero Patrizia Grimaldi Barbara Almoto Marilena Venturino Domenico Cento Maria Carola Narbone Francesco Trimarchi Sebastiano Coglitore Salvatore Cannavò 《BMC endocrine disorders》2006,6(1):1-8
Background
Most patients with growth hormone deficiency (GHD) show high body mass index. Overweight subjects, but GHD patients, were demonstrated to have high left ventricular mass index (LVMi) and abnormal LV geometric remodeling. We sought to study these characteristics in a group of GHD patients, in an attempt to establish the BMI-independent role of GHD.Methods
Fifty-four patients, 28 F and 26 M, aged 45.9 ± 13.1, with adult-onset GHD (pituitary adenomas 48.2%, empty sella 27.8%, pituitary inflammation 5.5%, cranio-pharyngioma 3.7%, not identified pathogenesis 14.8%) were enrolled. To minimize any possible interferences of BMI on the aim of this study, the control group included 20 age- and weight-matched healthy subjects. The LV geometry was identified by the relationship between LVMi (cut-off 125 g/m2) and relative wall thickness (cut-off 0.45) at echocardiography.Results
There was no significant between-group difference in resting cardiac morphology and function, nor when considering age-related discrepancy. The majority of patients had normal-low LVM/LVMi, but about one fourth of them showed higher values. These findings correlated to relatively high circulating IGF-1 and systolic blood pressure at rest. The main LV geometric pattern was eccentric hypertrophy in 22% of GHD population (26% of with severe GHD) and in 15% of controls (p = NS).Conclusion
Though the lack of significant differences in resting LV morphology and function, about 25% of GHD patients showed high LVMi (consisting of eccentric hypertrophy), not dissimilarly to overweight controls. This finding, which prognostic role is well known in obese and hypertensive patients, is worthy to be investigated in GHD patients through wider controlled trials. 相似文献95.
The most common parameters used to evaluate sperm quality are motility rate and duration and fertilization ability. In this study, chemical and biochemical parameters of sea bass (Dicentrarchus labrax) sperm were investigated to find an alternative method for evaluating sperm fertilization ability before and after cryopreservation. The biochemical and chemical analyses were performed with fresh and frozen-thawed sperm and seminal plasma. To cryopreserve sperm, 250-microl straws were used. Fertilization ability was evaluated by inseminating eggs (obtained from hormonally stimulated females) with fresh and cryopreserved sperm. The results revealed a linear relationship (P < 0.05) between semen fertilization capacity and some seminal plasma (beta-D-glucuronidase activity, potassium concentration) and sperm (ATP concentration, aspartate aminotransferase activity) parameters. Variations in semen fertilization rate could be best described by two multiple regression models: one including the sperm parameters and another including the seminal plasma parameters. For practical application, the use of simple regression models is of value. Fertilization rate in both fresh and cryopreserved sperm was reliably predicted by determining the ATP concentration or the beta-D-glucuronidase activity or both. 相似文献
96.
Maggiolini M Vivacqua A Fasanella G Recchia AG Sisci D Pezzi V Montanaro D Musti AM Picard D Andò S 《The Journal of biological chemistry》2004,279(26):27008-27016
A growing body of evidence concerning estrogen effects cannot be explained by the classic model of hormone action, which involves the binding to estrogen receptors (ERs) alpha and ERbeta and the interaction of the steroid-receptor complex with specific DNA sequences associated with target genes. Using c-fos proto-oncogene expression as an early molecular sensor of estrogen action in ERalpha-positive MCF7 and ER-negative SKBR3 breast cancer cells, we have discovered that 17beta-estradiol (E2), and the two major phytoestrogens, genistein and quercetin, stimulate c-fos expression through ERalpha as well as through an ER-independent manner via the G protein-coupled receptor homologue GPR30. The c-fos response is repressed in GPR30-expressing SKBR3 cells transfected with an antisense oligonucleotide against GPR30 and reconstituted in GPR30-deficient MDA-MB 231 and BT-20 breast cancer cells transfected with a GPR30 expression vector. GPR30-dependent activation of ERK1/2 by E2 and phytoestrogens occurs via a Gbetagamma-associated pertussis toxin-sensitive pathway that requires both Src-related and EGF receptor tyrosine kinase activities. The ability of E2 and phytoestrogens to regulate the expression of growth-related genes such as c-fos even in the absence of ER has interesting implications for understanding breast cancer progression. 相似文献
97.
98.
Sebastiano?SalleoEmail author Andrea?Nardini Fabio?Raimondo Maria?Assunta?Lo Gullo Francesca?Pace Paola?Giacomich 《Trees - Structure and Function》2003,17(4):367-375
The leaf miner Cameraria ohridella causes premature defoliation of Aesculus hippocastanum trees. Repeated defoliation has been reported to cause decrease in radial growth of trees and a progressive decline due to reduced production and allocation of photosynthates. Our study represents an attempt to estimate the impact of C. ohridella on annual wood increments and the hydraulic properties of the wood as well as on the dry mass of seeds. Twenty-two adult horse chestnut trees were selected, four of which had been chemically treated to prevent attack (controls). All other trees were heavily infested. The ground cover (GC) of each tree, measured from monthly hemispherical photographs, revealed that infested trees were completely defoliated in September and the slope of the GC-to-measurement dates relationship (named GC decrease index) was positively related to the number of mines per leaf. Anatomical observations showed that infested trees produced more wood per year than controls through more false rings with wider xylem conduits and, hence, with higher conductive area and theoretical flow. In fact, the theoretical flow was positively related to the defoliation intensity. In contrast, the allocation of photosynthates to seeds was strongly reduced in infested trees with respect to controls (up to 50% less). The hypothesis was advanced that horse chestnut trees reacted to C. ohridella attacks by increasing the hydraulic efficiency of the wood, thus ameliorating the water and nutrient supply to leaves between the spring and mid-summer and, therefore, compensating, at least partly, the reduced leaf lifespan. 相似文献
99.
Parkin Transcript Variants in Rat and Human Brain 总被引:3,自引:0,他引:3
Alternative splicing has an important role in expanding protein diversity. We have identified complementary DNA species from adult rat and fetal human brain encoding seven new splice variants of parkin, a gene mutated in autosomal recessive juvenile parkinsonism (ARJP). Alternative splicing affects almost all previously characterized exons, plus 3 new exons of 72, 156, and 180 nucleotides. This creates the potential to express hundreds of different isoforms. The encoded parkin isoforms have different amino acid composition, post-translational modifications, and, most important, molecular architectures. They diverge for the presence or absence of the ubiquitin-like domain, one or two C3HC4 ring fingers, the in-between ring fingers (IBR) domain, and a thiol proteases active site, which has not been previously characterized. Distinct expression patterns occur in primary cultures of neuronal and glial cells. Extensive splicing of parkin produces regional and structural diversity and may have important implications for the pathogenetic mechanisms underlying ARJP. 相似文献
100.
Merendino RA Salvo F Saija A Di Pasquale G Tomaino A Minciullo PL Fraccica G Gangemi S 《Mediators of inflammation》2003,12(2):127-128
Benign prostate hypertrophy (BPH) is the most common benign tumor in men due to obstruction of the urethra and, finally, uremia. Malondialdehyde (MDA) is a product derived from peroxidation of polyunsaturated fatty acids and related esters. Evaluation of MDA in serum represents a non-invasive biomarker of oxidative stress. Prostate-specific antigen (PSA) is a sensitive marker for prostatic hypertrophy and cancer. We analyzed MDA serum levels to evaluate the oxidative stress in BPH. To this end, 22 BPH patients and 22 healthy donors were enrolled. Data show an increase of MDA level in BPH patients and a positive correlation between PSA and MDA levels. In conclusion, we describe a previously unknown relationship between PSA and MDA as an index of inflammation and oxidative stress in BPH. 相似文献