998 resultados para Current injection


Relevância:

20.00% 20.00%

Publicador:

Resumo:

T his report presents population estimates for July 1, 1972 and provisional estimates for July 1, 1973, for counties and metropolitan areas prepared under the auspices of the Federal State Cooperative Program for Local Population Estimates. The objective of this program. is the development and publication of State - prepared estimates of the population of counties using uniform procedures largely standardized for data input and methodology. The methods used have been mutually agreed upon by the individual States and the Bureau of the Census on the basis of a test of methods against the 1970 census. For a more detailed description of the program.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This report presents population estimates for July 1, 1973 and provisional estimates for July 1, for counties and metropolitan areas prepared under the auspices of the Federal State Cooperative Program for Local Population Estimates. The objective of this program. is the development and publication of State - prepared estimates of the population of counties using uniform procedures largely standardized for data input and methodology. The methods used have been mutually agreed upon by the individual States and the Bureau of the Census on the basis of a test of methods against the 1970 census. For a more detailed description of the program.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An analytical model based on Bowen and Holman [1989] is used to prove the existence of instabilities due to the presence of a second extremum of the background vorticity at the front side of the longshore current. The growth rate of the so-called frontshear waves depends primarily upon the frontshear but also upon the backshear and the maximum and the width of the current. Depending on the values of these parameters, either the frontshear or the backshear instabilities may dominate. Both types of waves have a cross-shore extension of the order of the width of the current, but the frontshear modes are localized closer to the coast than are the backshear modes. Moreover, under certain conditions both unstable waves have similar growth rates with close wave numbers and angular frequencies, leading to the possibility of having modulated shear waves in the alongshore direction. Numerical analysis performed on realistic current profiles confirm the behavior anticipated by the analytical model. The theory has been applied to a current profile fitted to data measured during the 1980 Nearshore Sediment Transport Studies experiment at Leadbetter Beach that has an extremum of background vorticity at the front side of the current. In this case and in agreement with field observations, the model predicts instability, whereas the theory based only on backshear instability fai led to do so.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Injection of cells expressing the retroviral superantigen Mls-1 (Mtv-7 sag) into adult Mls-1- mice induces a strong immune response including both T- and B-cell activation. This model was used for studying qualitative aspects of the immune response in normal mice with a defined antigen-presenting cell (the B cell) and without the use of adjuvant. BALB/c mice were injected locally or systemically with Mls-1-expressing spleen cells from Mls-1-congenic BALB.D2 mice. Intravenous injection led to an initially strong expansion of Mls-1-reactive V beta 6+ CD4+ cells mainly in the spleen, to a large degree explained by the trapping of reactive cells, and a rapid down-regulation of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) production, consistent with the proposed tolerogenic property of B cells as antigen-presenting cells. However, these mice developed a slowly appearing but persistent B-cell response dominated by IgG1-producing cells, suggesting a shift in lymphokines produced rather than complete unresponsiveness. Subcutaneous injection into the hind footpad with the same number of cells led to a strong local response in the draining lymph node, characterized by a dramatic increase of V beta 6+ CD4+ T cells, local production of IL-2 and IFN-gamma and a strong but short-lived antibody response dominated by IgG2a-producing cells, characteristic of a T-helper type 1 (Th1) type of response. Both routes of injection led ultimately to deletion of reactive T cells and anergy, as defined by the inability to produce IL-2 upon in vitro stimulation with Mls-1. It is concluded that Mls-1 presented by B cells induces qualitatively different responses in vivo dependent on the route of injection. We propose that the different responses result from the migration of the injected cells to different micro-anatomical sites in the lymphoid tissue. Furthermore, these results suggest that B cells may function as professional antigen-presenting cells in vivo present in an appropriate environment.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

To analyze the effects of triamcinolone intravitreal injection on the wound healing processes after argon laser retinal photocoagulation, wild type C57BL/6J mice, 8-12 weeks old underwent a standard argon laser photocoagulation protocol. After pentobarbital anesthesia and pupil dilatation, argon laser lesions were induced (50microm, 400mW, 0.05s). Two photocoagulation impacts created two disc diameters from the optic nerve in both eyes. The photocoagulated mice were divided into four groups: Group I (n=12), photocoagulation controls, did not receive any intravitreous injection. Group II (n=12), received an intravitreous injection of 1microl of balanced salt solution (BSS). Group III (n=12), received an intravitreous injection of 1microl containing 15microg of triamcinolone acetonide (TAAC) in BSS. Two mice from each of these three groups were sacrificed at 1, 3, 7, 14 days and 2 and 4 months after photocoagulation. Group IV (n=10) received 1.5, 3, 7.5, 15, or 30microg of TAAC and were all sacrificed on day 14. The enucleated eyes were subjected to systematic analysis of the cellular remodeling processes taking place within the laser lesion and its vicinity. To this purpose, specific antibodies against GFAP, von Willebrand factor, F4/80 and KI67 were used for the detection of astrocytes, activated Müller cells, vascular endothelial cells, infiltrating inflammatory cells and actively proliferating cells. TUNEL reaction was also carried out along with nuclear DAPI staining. Temporal and spatial observations of the created photocoagulation lesions demonstrate that 24h following the argon laser beam, a localized and well-delineated affection of the RPE cells and choroid is observed in mice in Groups I and II. The inner retinal layers in these mice eyes are preserved while TUNEL positive (apoptotic) cells are observed at the retinal outer nuclear layer level. At this stage, intense staining with GFAP is associated with activated retinal astrocytes and Müller cells throughout the laser path. From day 3 after photocoagulation, dilated new choroidal capillaries are detected on the edges of the laser lesion. These processes are accompanied by infiltration of inflammatory cells and the presence of proliferating cells within the lesion site. Mice in Group III treated with 15microg/mul of triamcinolone showed a decreased number of infiltrating inflammatory cells and proliferating cells, which was not statistically significant compared to uninjected laser treated controls. The development of new choroidal capillaries on the edges of the laser lesion was also inhibited during the first 2 months after photocoagulation. However, on month 4 the growth of new vessels was observed in these mice treated with TAAC. Mice of Group IV did not show any development of new capillaries even with small doses. After argon laser photocoagulation of the mouse eye, intravitreal injection of triamcinolone markedly influenced the retina and choroid remodeling and healing processes. Triamcinolone is a powerful inhibitor of the formation of neovessels in this model. However, this inhibition is transient. These observations should provide a practical insight for the mode of TAAC use in patients with wet AMD.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND AND PURPOSE: APETx2, a toxin from the sea anemone Anthropleura elegantissima, inhibits acid-sensing ion channel 3 (ASIC3)-containing homo- and heterotrimeric channels with IC(50) values < 100 nM and 0.1-2 µM respectively. ASIC3 channels mediate acute acid-induced and inflammatory pain response and APETx2 has been used as a selective pharmacological tool in animal studies. Toxins from sea anemones also modulate voltage-gated Na(+) channel (Na(v) ) function. Here we tested the effects of APETx2 on Na(v) function in sensory neurones.¦EXPERIMENTAL APPROACH: Effects of APETx2 on Na(v) function were studied in rat dorsal root ganglion (DRG) neurones by whole-cell patch clamp.¦KEY RESULTS: APETx2 inhibited the tetrodotoxin (TTX)-resistant Na(v) 1.8 currents of DRG neurones (IC(50) , 2.6 µM). TTX-sensitive currents were less inhibited. The inhibition of Na(v) 1.8 currents was due to a rightward shift in the voltage dependence of activation and a reduction of the maximal macroscopic conductance. The inhibition of Na(v) 1.8 currents by APETx2 was confirmed with cloned channels expressed in Xenopus oocytes. In current-clamp experiments in DRG neurones, the number of action potentials induced by injection of a current ramp was reduced by APETx2.¦CONCLUSIONS AND IMPLICATIONS: APETx2 inhibited Na(v) 1.8 channels, in addition to ASIC3 channels, at concentrations used in in vivo studies. The limited specificity of this toxin should be taken into account when using APETx2 as a pharmacological tool. Its dual action will be an advantage for the use of APETx2 or its derivatives as analgesic drugs.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The cytotoxic T-cell and natural killer (NK)-cell lymphomas and related disorders are important but relatively rare lymphoid neoplasms that frequently are a challenge for practicing pathologists. This selective review, based on a meeting of the International Lymphoma Study Group, briefly reviews T-cell and NK-cell development and addresses questions related to the importance of precise cell lineage (αβ-type T cell, γδ T cell, or NK cell), the implications of Epstein-Barr virus infection, the significance of anatomic location including nodal disease, and the question of further categorization of enteropathy-associated T-cell lymphomas. Finally, developments subsequent to the 2008 World Health Organization Classification, including the recognition of indolent NK-cell and T-cell disorders of the gastrointestinal tract are presented.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Chronic low back pain attributed to lumbar disc degeneration poses a serious challenge to physicians. Surgery may be indicated in selected cases following failure of appropriate conservative treatment. For decades, the only surgical option has been spinal fusion, but its results have been inconsistent. Some prospective trials show superiority over usual conservative measures while others fail to demonstrate its advantages. In an effort to improve results of fusion and to decrease the incidence of adjacent segment degeneration, total disc replacement techniques have been introduced and studied extensively. Short-term results have shown superiority over some fusion techniques. Mid-term results however tend to show that this approach yields results equivalent to those of spinal fusion. Nucleus replacement has gained some popularity initially, but evidence on its efficacy is scarce. Dynamic stabilisation, a technique involving less rigid implants than in spinal fusion and performed without the need for bone grafting, represents another surgical option. Evidence again is lacking on its superiority over other surgical strategies and conservative measures. Insertion of interspinous devices posteriorly, aiming at redistributing loads and relieving pain, has been used as an adjunct to disc removal surgery for disc herniation. To date however, there is no clear evidence on their efficacy. Minimally invasive intradiscal thermocoagulation techniques have also been tried, but evidence of their effectiveness is questioned. Surgery using novel biological solutions may be the future of discogenic pain treatment. Collaboration between clinicians and basic scientists in this multidisciplinary field will undoubtedly shape the future of treating symptomatic disc degeneration.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Prophylactic human papillomavirus (HPV) L1 virus like particle (VLP) vaccines have been shown, in large clinical trials, to be very immunogenic, well-tolerated and highly efficacious against genital disease caused by the vaccine HPV types. However these vaccines, at the present, protect against only two of the 15 oncogenic genital HPV types, they are expensive, delivered by intramuscular injection and require a cold chain. The challenges are to develop cheap, thermo-stable vaccines that can be delivered by non-injectable methods that provide long term (decades) protection at mucosal surfaces to most, if not all, oncogenic HPV types that is as good as the current VLP vaccines. Current approaches include L1 capsomers, L2 protein and peptides, delivery via recombinant L1 bacterial and viral vectors and large-scale VLP production in plants. Rational design and successful development of such vaccines will be based on an understanding of the immune response, and particularly the 'cross talk' between the innate and adaptive responses. This will be central in the development of adjuvants and vaccine formulations that induce the response to provide effective protection.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

PURPOSE: To evaluate the potential delay of the retinal degeneration in rd1/rd1 mice using recombinant human glial cell line-derived neurotrophic factor (rhGDNF) encapsulated in poly(D,L-lactide-co-glycolide) (PLGA) microspheres. METHODS: rhGDNF-loaded PLGA microspheres were prepared using a water in oil in water (w/o/w) emulsion solvent extraction-evaporation process. In vitro, the rhGDNF release profile was assessed using radiolabeled factor. In vivo, rhGDNF microspheres, blank microspheres, or microspheres loaded with inactivated rhGDNF were injected into the vitreous of rd1/rd1 mice at postnatal day 11 (PN11). The extent of retinal degeneration was examined at PN28 using rhodopsin immunohistochemistry on whole flat-mount retinas, outer nuclear layer (ONL) cell counting on histology sections, and electroretinogram tracings. Immunohistochemical reactions for glial fibrillary acidic protein (GFAP), F4/80, and rhodopsin were performed on cryosections. RESULTS: Significant delay of rod photoreceptors degeneration was observed in mice receiving the rhGDNF-loaded microspheres compared to either untreated mice or to mice receiving blank or inactivated rhGDNF microspheres. The degeneration delay in the eyes receiving the rhGDNF microspheres was illustrated by the increased rhodopsin positive signals, the preservation of significantly higher number of cell nuclei within the ONL, and significant b-wave increase. A reduction of the subretinal glial proliferation was also observed in these treated eyes. No significant intraocular inflammatory reaction was observed after the intravitreous injection of the various microspheres. CONCLUSIONS: A single intravitreous injection of rhGDNF-loaded microspheres slows the retinal degeneration processes in rd1/rd1 mice. The use of injectable, biodegradable polymeric systems in the vitreous enables the efficient delivery of therapeutic proteins for the treatment of retinal diseases.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

PURPOSE OF REVIEW: Oculopalatal tremor (OPT) is an acquired disorder resulting from the interruption of a specific brainstem circuitry, the dentato-rubro-olivary pathway or Guillain-Mollaret triangle. The recent literature on OPT and olivary hypertrophy was reviewed with specific interest regarding causes, diagnostic procedures, physiopathology and therapies. RECENT FINDINGS: OPT is associated with inferior olivary hypertrophy, and recent findings have provided a better understanding of its intimate mechanisms. A dual-mechanism model, combining an oscillator (inferior olive) and a modulator/amplifier (cerebellum), best explains the development of OPT. Electrotonic coupling and specific Ca channels contribute to oscillations of inferior olivary nucleus neurons in OPT. Improvement of visual symptoms can be achieved with oral gabapentin or memantine. SUMMARY: Both the neuronal circuitry and the physiopathology of OPT are now better understood. This opens up an era of specific therapy for this rare cause of disabling oscillopsia.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: As the long-term survival of pancreatic head malignancies remains dismal, efforts have been made for a better patient selection and a tailored treatment. Tumour size could also be used for patient stratification. METHODS: One hundred and fourteen patients underwent a pancreaticoduodenectomy for pancreatic adenocarcinoma, peri-ampullary and biliary cancer stratified according to: ≤20 mm, 21-34 mm, 35-45 mm and >45 mm tumour size. RESULTS: Patients with tumour sizes of ≤20 mm had a N1 rate of 41% and a R1/2 rate of 7%. The median survival was 3.4 years. N1 and R1/2 rates increased to 84% and 31% for tumour sizes of 21-34 mm (P = 0.0002 for N, P = 0.02 for R). The median survival decreased to 1.6 years (P = 0.0003). A further increase in tumour size of 35-45 mm revealed a further increase of N1 and R1/2 rates of 93% (P < 0.0001) and 33%, respectively. The median survival was 1.2 years (P = 0.004). Tumour sizes >45 mm were related to a further decreased median survival of 1.1 years (P = 0.2), whereas N1 and R1/2 rates were 87% and 20%, respectively. DISCUSSION: Tumour size is an important feature of pancreatic head malignancies. A tumour diameter of 20 mm seems to be the cut-off above which an increased rate of incomplete resections and metastatic lymph nodes must be encountered and the median survival is reduced.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The purpose of this study was to evaluate the efficacy of a Coulomb Controlled Iontophoresis system (CCI) in the local delivery of corticosteroids for the treatment of uveitis. The therapeutic efficacy of Dexamethasone (Dex) administered by CCI was compared to systemic injection and to topical application with the iontophoresis apparatus in the absence of electrical current. The evaluation was done in the treatment of the endotoxin-induced uveitis (EIU) model, and in the effect on TNF gene expression in the iris/ciliary body as well as in the retina and on TNF levels in aqueous humor and vitreous. Dex was administered either at the time of LPS injection or 5 hours later. For iontophoresis, we used a 1 ml reservoir-electrode covering the cornea, the limbus, and the first millimeter of the sclera. The applied electrical current was of 400 microA during four minutes with a total surface charge of 0.4 C cm-2. EIU was evaluated by clinical examination, by counts of intraocular inflammatory cells on histological sections, and by measuring the protein levels in the aqueous humor and in the vitreous. The TNF-alpha gene expression in the iris and ciliary body, and in the retina was evaluated by RT-PCR. The systemic effect of Dex delivered by CCI was evaluated on the level of serum TNF-alpha in EIU. Our results demonstrated that local administration of Dex by CCI inhibited anterior and posterior signs of intraocular inflammation as effectively as systemic administration, with no effect on systemic level of TNF. In the anterior and posterior segments of the eye, the protein exudation. TNF levels and the cellular infiltration were inhibited. The TNF-alpha gene expression was inhibited in the anterior as well as the posterior segment of the eye. No clinical nor histological damage were caused by the CCI apparatus. In conclusion, CCI administration of Dex allows for a therapeutic effect on the posterior as well as the anterior segment of the eye, and may present a viable alternative to systemic administration of glucocorticoids in severe ocular inflammations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We have investigated the effect of extracellular proteases on the amiloride-sensitive Na+ current (INa) in Xenopus oocytes expressing the three subunits alpha, beta, and gamma of the rat or Xenopus epithelial Na+ channel (ENaC). Low concentrations of trypsin (2 microg/ml) induced a large increase of INa within a few minutes, an effect that was fully prevented by soybean trypsin inhibitor, but not by amiloride. A similar effect was observed with chymotrypsin, but not with kallikrein. The trypsin-induced increase of INa was observed with Xenopus and rat ENaC, and was very large (approximately 20-fold) with the channel obtained by coexpression of the alpha subunit of Xenopus ENaC with the beta and gamma subunits of rat ENaC. The effect of trypsin was selective for ENaC, as shown by the absence of effect on the current due to expression of the K+ channel ROMK2. The effect of trypsin was not prevented by intracellular injection of EGTA nor by pretreatment with GTP-gammaS, suggesting that this effect was not mediated by G proteins. Measurement of the channel protein expression at the oocyte surface by antibody binding to a FLAG epitope showed that the effect of trypsin was not accompanied by an increase in the channel protein density, indicating that proteolysis modified the activity of the channel present at the oocyte surface rather than the cell surface expression. At the single channel level, in the cell-attached mode, more active channels were observed in the patch when trypsin was present in the pipette, while no change in channel activity could be detected when trypsin was added to the bath solution around the patch pipette. We conclude that extracellular proteases are able to increase the open probability of the epithelial sodium channel by an effect that does not occur through activation of a G protein-coupled receptor, but rather through proteolysis of a protein that is either a constitutive part of the channel itself or closely associated with it.