307 research outputs found
Morphological evidence that the molecularly determined Ciona intestinalis type A and type B are different species: Ciona robusta and Ciona intestinalis
Ciona intestinalis is considered a widespread and easily recognizable tunicate, the sister group of vertebrates. In recent years, molecular studies suggested that C. intestinalis includes at least two cryptic species, named 'type A' and 'type B', morphologically indistinguishable. It is dramatic to certify that two different species may be hidden under the name of a species widely used as a model species in biological researches. This raised the problem of identifying diagnostic morphological characters capable of distinguishing these types. We compared the morphology of specimens belonging to the two types and found that only type A specimens possess tunic tubercular prominences, allowing unambiguous discrimination. Remarkably, these structures were already described as distinctive of the Japanese species Ciona robusta, Hoshino and Tokioka, 1967; later synonymized under C. intestinalis (sensu Millar, 1953). In this study, we have confirmed that C. intestinalis type A corresponds to C. robusta. Based on the geographic distribution of C. intestinalis type B, and considering that the original C. intestinalis species was described from North European waters, we determined that C. intestinalis type B corresponds to C. intestinalis as described by Millar in 1953 and possibly to Linnaeus' Ascidia intestinalis L., 1767 for which we have deposited a neotype (from Roscoff, France) and for which we retain the name Ciona intestinalis (Linnaeus, 1767)
A novel electromagnetic tracking system for surgery navigation
Objective: This paper proposes the development of a novel electromagnetic tracking system for navigation surgery. Main objective is to provide a system able to operate in a wide tracking volume to make easier and efficient the surgical procedures by assuring high measurement accuracy. Methods: A new field generator consisting in five transmitting coils excited with Frequency Division Multiplexing technique has been developed. Attention is devoted to designing and arrangement of the coils to assure high sensitivity, system scalability and a homogeneous magnetic field inside working volume. A suitable technique based on Look-Up-Table is applied for sensor position calculation and an anthropomorphic robot is used for table calibration. Results: Experimental tests highlight a good repeatability of the measurement data and a negligible noise influence for the proposed system. The obtained tracking volume is wider with respect to the commercial tracking device used in surgical applications and seem promising. Conclusion: The main characteristic of the developed system consists of: scalable and modular configuration of Field Generator, high measured sensitivity due to the increased number of transmitting coils with respect to the classical configuration and large tracking volume. The development of the proposed magnetic tracking systems with high accuracy and wide working volume allows to promote broader utilization of advantaged techniques in surgery procedures for both improving the effectiveness and decreasing the invasiveness of medical interventions
Graminex pollen: phenolic pattern, colorimetric analysis and protective effects in immortalized prostate cells (PC3) and rat prostate challenged with LPS
Prostatitis, a general term describing prostate inflammation, is a common disease that
could be sustained by bacterial or non-bacterial infectious agents. The efficacy of herbal extracts with
antioxidant and anti-inflammatory effects for blunting the burden of inflammation and oxidative
stress, with possible improvements in clinical symptoms, is under investigation. Pollen extracts have
been previously reported as promising agents in managing clinical symptoms related to prostatitis.
The aim of the present work was to evaluate the protective effects of Graminex pollen (GraminexTM,
Deshler, OH, USA), a commercially available product based on standardized pollen extracts, in rat
prostate specimens, ex vivo. In this context, we studied the putative mechanism of action of
pollen on multiple inflammatory pathways, including the reduction of prostaglandin E2 (PGE2),
nuclear factor kappa-light-chain-enhancer of activated B cells (NFB), and malondialdehyde (MDA),
whose activities were significantly increased by inflammatory stimuli. We characterized by means
of chromatographic and colorimetric studies the composition of Graminex pollen to better correlate
the activity of pollen on immortalized prostate cells (PC3), and in rat prostate specimens challenged
with Escherichia coli lipopolysaccharide (LPS). We found that Graminex pollen was able to reduce
radical oxygen species (ROS) production by PC3 cells and MDA, NFB mRNA, and PGE2 levels,
in rat prostate specimens. According to our experimental evidence, Graminex pollen appears to be a
promising natural product for the management of the inflammatory components in the prostate
UV radiation promotes flavonoid biosynthesis, while negatively affecting the biosynthesis and de-epoxidation of xanthophylls: consequence for photoprotection?
There is evidence that UV radiation may detrimentally affect the biosynthesis of carotenoids, particularly de-epoxided xanthophylls, while strongly promoting phenylpropanoid, particularly flavonoid biosynthesis in a range of taxa. Here we tested the hypothesis that mesophyll flavonoids might protect chloroplasts from UV-induced photo-oxidative damage, by partially compensating for the UV-induced depression of xanthophyll biosynthesis. To test this hypothesis we grew two members of the Oleaceae family, Ligustrum vulgare L. and Phillyrea latifolia L., under either partial shading or fully exposed to sunlight, in the presence or in the absence of UV radiation. The examined species, which display very similar flavonoid composition, largely differ in their ability to limit the transmission of UV and visible light through the leaf and, hence, in the accumulation of flavonoids in mesophyll cells. We conducted measurements of photosynthesis, chlorophyll a fluorescence kinetics, the concentrations of individual carotenoids and phenylpropanoids at the level of whole-leaf, as well as the content of epidermal flavonoids. We also performed multispectral fluorescence micro-imaging to unveil the intra-cellular distribution of flavonoids in mesophyll cells. UV radiation decreased the concentration of carotenoids, particularly of xanthophylls, while greatly promoting the accumulation of flavonoids in palisade parenchyma cells. These effects were much greater in L. vulgare than in P. latifolia. UV radiation significantly inhibited the de-epoxidation of xanthophyll cycle pigments, while enhancing the concentration of luteolin, and particularly of quercetin glycosides. Flavonoids accumulated in the vacuole and the chloroplasts in palisade cells proximal to the adaxial epidermis. We hypothesize that flavonoids might complement the photo-protective functions of xanthophylls in the chloroplasts of mesophyll cells exposed to the greatest doses of UV radiation. However, UV radiation might result in adaxial mesophyll cells being less effective in dissipating the excess of radiant energy, e.g., by decreasing their capacity of thermal dissipation of excess visible light in the chloroplast
Metabolic plasticity in the hygrophyte Moringa oleifera exposed to water stress
Over the past decades, introduction of many fast-growing hygrophilic, and economically valuable plants into xeric environments has occurred. However, production and even survival of these species may be threatened by harsh climatic conditions unless an effective physiological and metabolic plasticity is available. Moringa oleifera Lam., a multipurpose tree originating from humid sub-tropical regions of India, is widely cultivated in many arid countries because of its multiple uses. We tested whether M. oleifera can adjust primary and secondary metabolism to efficiently cope with increasing water stress. It is shown that M. oleifera possesses an effective isohydric behavior. Water stress induced a quick and strong stomatal closure, driven by abscisic acid (ABA) accumulation, and leading to photosynthesis inhibition with consequent negative effects on biomass production. However, photochemistry was not impaired and maximal fluorescence and saturating photosynthesis remained unaffected in stressed leaves. We report for the first time that M. oleifera produces isoprene, and show that isoprene emission increased three-fold during stress progression. It is proposed that higher isoprene biosynthesis helps leaves cope with water stress through its antioxidant or membrane stabilizing action, and also indicates a general MEP (methylerythritol 4-phosphate) pathway activation that further helps protect photosynthesis under water stress. Increased concentrations of antioxidant flavonoids were also observed in water stressed leaves, and probably cooperate in limiting irreversible effects of the stress in M. oleifera leaves. The observed metabolic and phenotypic plasticity may facilitate the establishment of M. oleifera in xeric environments, sustaining the economic and environmental value of this plant
The Role of Congestion Biomarkers in Heart Failure with Reduced Ejection Fraction
: In heart failure with reduced ejection fraction, edema and congestion are related to reduced cardiac function. Edema and congestion are further aggravated by chronic kidney failure and pulmonary abnormalities. Furthermore, together with edema/congestion, sodium/water retention is an important sign of the progression of heart failure. Edema/congestion often anticipates clinical symptoms, such as dyspnea and hospitalization; it is associated with a reduced quality of life and a major risk of mortality. It is very important for clinicians to predict the signs of congestion with biomarkers and, mainly, to understand the pathophysiological findings that underlie edema. Not all congestions are secondary to heart failure, as in nephrotic syndrome. This review summarizes the principal evidence on the possible roles of the old and new congestion biomarkers in HFrEF patients (diagnostic, prognostic, and therapeutic roles). Furthermore, we provide a description of conditions other than congestion with increased congestion biomarkers, in order to aid in reaching a differential diagnosis. To conclude, the review focuses on how congestion biomarkers may be affected by new HF drugs (gliflozins, vericiguat, etc.) approved for HFrEF
Genotypic and phenotypic characterization of Escherichia coli isolates recovered from the uterus of mares with fertility problems
Escherichia coli is the bacterial pathogen most frequently associated with mare infertility. Here, we characterized 24 E. coli strains isolated from mares which presented signs of endometritis and infertility from a genotypic and phenotypic point of view. The majority of the isolates belonged to phylogenetic group B1 (9/24, 37.5%). Regarding antibiotic resistance profiles, 10 out of 24 (41.7%) were multidrug-resistant (MDR). Moreover, 17 out of 24 (70.8%) were strong or moderate biofilm producers, and of these eight were MDR strains. Interestingly, 21 out of 24 (87.5%) E. coli strains were phenotypically resistant to ampicillin and 10 of them were also resistant to amoxicillin with clavulanic acid. Regarding the presence of selected virulence factors, 50% of the examined strains carried at least three of them, with fimH detected in all strains, and followed by kpsMTII (11/24, 45.9%). No strain was able to invade HeLa cell monolayers. No relevant differences for all the investigated characteristics were shown by strains that grew directly on plates versus strains requiring the broth-enrichment step before growing on solid media. In conclusion, this work provides new insight into E. coli strains associated with mares' infertility. These results broaden the knowledge of E. coli and, consequently, add useful information to improve prevention strategies and therapeutic treatments contributing to a significant increase in the pregnancy rate in mares
Efficacy of new medical therapies in patients with heart failure, reduced ejection fraction and chronic kidney disease already receiving neurohormonal inhibitors: a network meta-analysis
Clinical and Metabolic Signature of UNC13A rs12608932 Variant in Amyotrophic Lateral Sclerosis
MK-4101 - a potent inhibitor of the hedgehog pathway - is highly active against medulloblastoma and basal cell carcinoma
Aberrant activation of the Hedgehog (Hh) signaling pathway is implicated in the pathogenesis of many cancers, including medulloblastoma and basal cell carcinoma (BCC). In this study, using neonatally irradiated Ptch1+/- mice as a model of Hh-dependent tumors, we investigated the in vivo effects of MK-4101, a novel SMO antagonist, for treatment of medulloblastoma and BCC. Results clearly demonstrated a robust antitumor activity of MK-4101, achieved through the inhibition of proliferation and induction of extensive apoptosis in tumor cells. Of note, beside antitumor activity on transplanted tumors, MK-4101 was highly efficacious against primary medulloblastoma and BCC developing in the cerebellum and skin of Ptch1+/- mice. By identifying the changes induced by MK-4101 in gene expression profiles in tumors, we also elucidated the mechanism of action of this novel, orally administrable compound. MK-4101 targets the Hh pathway in tumor cells, showing the maximum inhibitory effect on Gli1. MK-4101 also induced deregulation of cell cycle and block of DNA replication in tumors. Members of the IGF and Wnt signaling pathways, were among the most highly deregulated genes by MK-4101, suggesting that the interplay among Hh, IGF and Wnt is crucial in Hh-dependent tumorigenesis. Altogether, the results of this preclinical study support a therapeutic opportunity for MK-4101 in the treatment of Hh-driven cancers, also providing useful information for combination therapy with drugs targeting pathways cooperating with Hh oncogenic activity
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