525 research outputs found
Antifungal effect and reduction of Ulmus minor symptoms to Ophiostoma novo-ulmi by carvacrol and salicylic acid
There are still no effective means to control Dutch elm disease (DED), caused by the vascular fungi Ophiostoma ulmi and O. novo-ulmi. Plant phenolics may provide a new strategy for DED control, given their known antifungal activity against pathogens and their involvement in plant defence mechanisms. The in vitro antifungal activity of salicylic acid, carvacrol, thymol, phenol, o-cresol, m-cresol, p-cresol, and 2,5-xylenol against the DED pathogens was tested. Also, the protective effect of watering Ulmus minor seedlings with these compounds was tested against O. novo-ulmi. Salicylic acid, carvacrol, and thymol showed the strongest antifungal in vitro activity, while carvacrol and salicylic acid provided the strongest in vivo protection against O. novo-ulmi (63 and 46% reduction of leaf wilting symptoms with respect to controls, respectively). The effect of the treatments on tree phenology was low, and a significant negative relation was observed between the number of days to bud burst and the leaf wilting symptoms after inoculation, probably determined by genetic differences among the elm tree progenies used. The treatments with salicylic acid, carvacrol and thymol induced the highest shift in phenolic metabolite profile with respect to control trees. The protective effect of carvacrol and salicylic acid is discussed in terms of their combined activity as antifungal compounds and as inductors of tree defence responses
Cerebroespinal fluid control of neurogenesis induced by retinoic acid during early brain development
Producción CientíficaEmbryonic-cerebrospinal fluid (E-CSF) plays crucial roles in early brain development including the control
of neurogenesis. Although FGF2 and lipoproteins present in the E-CSF have previously been shown
to be involved in neurogenesis, the main factor triggering this process remains unknown. E-CSF contains
all-trans-retinol and retinol-binding protein involved in the synthesis of retinoic acid (RA), a neurogenesis
inducer. In early chick embryo brain, only the mesencephalic-rombencephalic isthmus (IsO) is able to
synthesize RA. Here we show that in chick embryo brain development: (1) E-CSF helps to control RA synthesis
in the IsO by means of the RBP and all-trans-retinol it contains; (2) E-CSF has retinoic acid activity,
which suggests it may act as a diffusion pathway for RA; and (3) the influence of E-CSF on embryonic
brain neurogenesis is to a large extent due to its involvement in RA synthesis. These data help to
understand neurogenesis from neural progenitor cells2015-05-2
Chondroitin sulphate proteoglycan is involved in lens vesicle morphogenesis in chick embryos
Producción CientíficaProteoglycans have been implicated in the invagination and formation of various embryonal cavitied
primordia. In this paper the expression of chondroitin sulphate proteoglycan is analysed (CSPG) in the lens
primordium during lens vesicle formation, and demonstrate that this proteoglycan has a speci®c
distribution pattern with regard to invagination and fusion processes in the transformation of placode into
lens vesicle. More speci®cally, CSPG was detached in: (1) the apical surface of lens epithelial cells, where
early CSPG expression was observed in the whole of the lens placode whilst in the vesicle phase it was
restricted to the posterior epithelium; (2) intense CSPG expression in the basal lamina, which remained
constant for the entire period under study; (3) CSPG expression in the intercellular spaces of the lens
primordium epithelium, which increased during the invagination of the primordium and which at the
vesicle stage was more evident in the posterior epithelium; and (4) CSPG expression on the edges of the
lens placode both prior to and during fusion. Treatment with b-D-xyloside causes signi®cant CSPG
depletion in the lens primordium together with severe alterations in the invagination and fusion of the
lens vesicle; this leads to the formation of lens primordia which in some cases remain practically ¯at or
show partial invagination defects or fusion disruption. Similar results were obtained by enzyme digestion
with chondroitinase AC but not with type II heparinase, which indicates that alterations induced by b-Dxyloside
were due to interference in CSPG synthesis. The ®ndings demonstrate that CSPG is a common
component of the lens primordium at the earliest developmental stages during which it undergoes speci®c
modi®cations. It also includes experimental evidence to show that `in vivo' CSPG plays an important role
in the invagination and fusion processes of the lens primordium. # 2001 Academic Press
Key words: lens development; CSPG; b-D-xyloside; extracellular matrix; epithelial invaginatio
Role of interleukin 1B in the control of neuropithelial proliferation and differentiation of the spinal cord during development
Producción CientíficaInterleukin-1b (IL-1b) is an important trophic factor in the nervous system (NS). IL-1b is ubiquitously expressed from very early stages during the development of the amphibian NS and its action has been demonstrated in vitro on survival, proliferation and differ- entiation in mammalian embryos. In this report, we show that IL-1b is immunocytochemically expressed in embryonic spinal cord from early stages, both in rat (embryonic day 12) and in chicken (stage 17-HH), in neuroepithelial cells and nerve fibres, dorsal root ganglia, anterior and posterior roots of the spinal nerves, and in the fibres of these nerves. Our in vivo experiments on chick embryos, with micro- beads impregnated with IL-1b implanted laterally to the spinal cord at the level of the wing anlage, demonstrate that this cytokine pro- duces a statistically significant increase in nuclear incorporation of BrdU at the dorsal level and a reduction of this at the ventral level, whereas local immunoblocking with anti-IL-1b antibodies causes a dorsal reduction of BrdU incorporation and alters ventral differen- tiation. These data demonstrate that IL-1b plays a part in controlling proliferation and early differentiation during the development of the spinal cord in chick embryos
Prenatal expression of interleukin 1B and interleukin 6 in the rat pituitary gland
Producción CientíficaIt is known that interleukin 1b (IL-1b) and interleukin 6 (IL-6) are expressed post-natally in normal and
tumoral cells in the anterior pituitary, and that they play a role in both the liberation of different hormones
and in the growth, proliferation and tumor formation of the pituitary gland. However, their
expression and role during embryonic and fetal development remain unknown. We have performed an
immunocytochemistry study of prenatal expression and distribution of IL-1b and IL-6 in isolated embryonic
rat Rathke’s pouch prior to birth, more specifically between 13.5 and 19.5 days p.c. Western-blot
analysis carried out on 19.5-day p.c. embryos showed positive immunolabelling for IL-1b and IL-6. These
interleukins were initially expressed simultaneously in the rostral and ventral portions of Rathke’s pouch
in 15.5-day p.c. embryos, and this expression progressed caudodorsally in later developmental stages,
extending to most of the hypophysis before birth. The number of cells expressing these interleukins
increased throughout this period: 48.22% of anterior pituitary cells expressed IL-6 in 19.5-day embryos,
whilst IL-1b was positive in 39.8% of the cells. Moreover, we have demonstrated that some adenohypophyseal
cells co-express both interleukins. Such findings represent the first step towards an understanding
of the physiological role of these interleukins in anterior pituitary development
Early embryonic brain development in rats requieres the trophic influence of cerebrospinal fluid
Producción CientíficaParticularly evCerebrospinal fluid has shown itself to be an essential brain component during development. This is parident at the earliest stages of development where a lot of research, performed mainly in chick embryos, supports the evidence that cerebrospinal fluid is involved in different mechanisms controlling brain growth and morphogenesis, by exerting a trophic effect on neuroepithelial precursor cells (NPC) involved in controlling the behaviour of these cells. Despite it being known that cerebrospinal fluid in mammals is directly involved in corticogenesis at fetal stages, the influence of cerebrospinal fluid on the activity of NPC at the earliest stages of brain development has not been demonstrated. Here, using
‘‘in vitro’’ organotypic cultures of rat embryo brain neuroepithelium in order to expose NPC to or deprive them of cerebrospinal fluid, we show that the neuroepithelium needs the trophic influence of cerebrospinal fluid to undergo normal rates of cell survival, replication and neurogenesis, suggesting that NPC are not self-sufficient to induce their normal activity. This data shows that cerebrospinal fluid is an essential component in chick and rat early brain development, suggesting that its influence could be constant in higher vertebrates
Oxford phase 3 unicondylar knee arthroplasty through a minimally invasive approach: long-term results
Producción CientíficaSurgical treatment options for medial compartment osteoarthritis of the knee include high tibial osteotomy, total knee arthroplasty or unicompartmental knee arthroplasty (UKA), depending on the patient's age, level of physical activity and the degree of deformity.
METHODS:In this study, we evaluated the long-term results of patients who underwent the Oxford cemented meniscal-bearing unicondylar knee prosthesis through a minimally invasive approach including a clinical, functional and radiographic assessment.
RESULTS:Favourable clinical and radiological outcomes were registered overall at ten years after surgery. Overall results of UKA according to the American Knee Society (AKS) using Insall's criteria showed an excellent or good outcome for 492 knees (96.28 %), fair for 11 (2.15 %) and poor for eight (1.57 %) in the post-operative long term.
CONCLUSIONS:We believe that with appropriate surgical technique, patient selection, prosthetic design and specific training, surgeons should achieve good outcomes with the added advantages of a minimally invasive approach. High volume for this technique is important in our opinio
Chondroitin sulphate mediated fusion of brain: neural folds in rat embryons
Producción CientíficaPrevious studies have demonstrated that during neural fold fusion in different species, an apical extracellular material rich in glycoconjugates is involved. However, the composi- tion and the biological role of this material remain undeter- mined. In this paper, we show that this extracellular matrix in rat increases notably prior to contact between the neural folds, suggesting the dynamic behaviour of the secretory process. Immunostaining has allowed us to demonstrate that this extracellular matrix contains chondroitin sulphate proteoglycan (CSPG), with a spatio-temporal distribution pattern, suggesting a direct relationship with the process of adhesion. The degree of CSPG involvement in cephalic neu- ral fold fusion in rat embryos was determined by treatment with specific glycosidases. In vitro rat embryo culture and microinjection techniques were employed to carry out se- lective digestion, with chondroitinase AC, of the CSPG on the apical surface of the neural folds; this was done immediately prior to the bonding of the cephalic neural folds. In all the treated embryos, cephalic defects of neural fold fusion could
tant role in the fusion of the cephalic neural folds in rat em- bryos, which implies that this proteoglycan could be in- volved in cellular recognition and adhesion.
Abbreviations used in this paper
CSPG chondroitin sulphate proteoglycan
HSPG heparan sulphate proteoglycan
PBS phosphate-buffered saline
SEM scanning electron microscopy
be detected. These results show that CSPG plays an impor
A generalized Hill-Wheeler ansatz
The Hill-Wheeler ansatz for the total wave function, within the Generator Coordinate Method framework, is generalized by recourse to the theory of distributions. The ensuing approach allows one to obtain a basis that spans the collective subspace, without having to deal explicitly with the eigenvectors and eigenvalues of the overlap kernel. Applications to an exactly soluble model and anharmonic vibrations illustrate the present treatment.Facultad de Ciencias Exacta
RIPK1 is a critical modulator of both tonic and TLR-responsive inflammatory and cell death pathways in human macrophage differentiation
In this study, we took advantage of human-induced pluripotent stem cells (hiPSC) and CRISPR/Cas9 technology to investigate the potential roles of RIPK1 in regulating hematopoiesis and macrophage differentiation, proinflammatory activation, and cell death pathways. Knock-out of RIPK1 in hiPSCs demonstrated that this protein is not required for erythro-myeloid differentiation. Using a well-established macrophage differentiation protocol, knock-out of RIPK1 did not block the differentiation of iPSC-derived macrophages, which displayed a similar phenotype to WT hiPSC-derived macrophages. However, knock-out of RIPK1 leads to a TNFα-dependent apoptotic death of differentiated hiPSC-derived macrophages (iPS-MΦ) and progressive loss of iPS-MΦ production irrespective of external pro-inflammatory stimuli. Live video analysis demonstrated that TLR3/4 activation of RIPK1 KO hiPSC-derived macrophages triggered TRIF and RIPK3-dependent necroptosis irrespective of caspase-8 activation. In contrast, TLR3/4 activation of WT macrophages-induced necroptosis only when caspases were inhibited, confirming the modulating effect of RIPK1 on RIPK3-mediated necroptosis through the FADD, Caspase-8 pathway. Activation of these inflammatory pathways required RIPK3 kinase activity while RIPK1 was dispensable. However, loss of RIPK1 sensitizes macrophages to activate RIPK3 in response to inflammatory stimuli, thereby exacerbating a potentially pathological inflammatory response. Taken together, these results reveal that RIPK1 has an important role in regulating the potent inflammatory pathways in authentic human macrophages that are poised to respond to external stimuli. Consequently, RIPK1 activity might be a valid target in the development of novel therapies for chronic inflammatory diseases.España, MINECO/FEDER SAF2015-64171
- …