892 resultados para åk 4-6
Resumo:
Multiple extracellular mitogens are involved in the pathogenesis of proliferative forms of glomerulonephritis (GN), In vitro studies demonstrate the pivotal role of extracellular signal-regulated kinase (ERK) in the regulation of cellular proliferation in response to extracellular mitogens. In this study, we examined whether this kinase, as a convergence point of mitogenic stimuli, is activated in proliferative GN in vivo, Two different proliferative forms of anti-glomerular basal membrane (GEM) GN in rats were induced and whole cortical tissue as well as isolated glomeruli examined using kinase activity assays and Western blot analysis, Administration of rabbit anti-rat GEM serum to rats, preimmunized with rabbit IgG, induced an accelerated crescentic anti-GEM GN. A significant increase in cortical, and more dramatically glomerular ERK activity was detected at 1, 3, and 7 d after induction of GN, Immunization of Wistar-Kyoto rats with bovine GEM also induced a crescentic anti-GBM GN with an increase of renal cortical ERK activity after 4, 6, and 8 wk, ERK is phosphorylated and activated by the MAP kinase/ERK kinase (MEK), We detected a significant increase in the expression of glomerular MEK in the accelerated form of anti-GEM CN, providing a possible mechanism of long-term activation of ERK in this disease model, In contrast to ERK, activation of stress-activated protein kinase was only detectable at early stages of proliferative GN, indicating these related kinases to serve distinct roles in the pathogenesis of GN, Our observations point to ERK as a putative mediator of the proliferative response to immune injury in GN and suggest that upregulation of MEK is involved in the long-term regulation of ERK in vivo.
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High-affinity nitrate transport was examined in intact root hair cells of Arabidopsis thaliana using electrophysiological recordings to characterise the response of the plasma membrane to NO3-challenge and to quantify transport activity. The NO3--associated membrane current was determined using a three-electrode voltage clamp to bring membrane voltage under experimental control and to compensate for current dissipation along the longitudinal cell axis. Nitrate transport was evident in the roots of seedlings grown in the absence of a nitrogen source, but only 4-6 days postgermination. In 6-day-old seedlings, additions of 5-100 μm NO3-to the bathing medium resulted in membrane depolarizations of 8-43 mV, and membrane voltage (Vm) recovered on washing NO3-from the bath. Voltage clamp measurements carried out immediately before and following NO3-additions showed that the NO3--evoked depolarizations were the consequence of an inward-directed current that appeared across the entire range of accessible voltages (-300 to +50 mV). Both membrane depolarizations and NO3--evoked currents recorded at the free-running voltage displayed quasi-Michaelian kinetics, with apparent values for Km of 23 ± 6 and 44 ± 11 μm, respectively and, for the current, a maximum of 5.1 ± 0.9 μA cm-2. The NO3-current showed a pronounced voltage sensitivity within the normal physiological range between -250 and -100 mV, as could be demonstrated under voltage clamp, and increasing the bathing pH from 6.1 to 7.4-8.0 reduced the current and the associated membrane depolarizations 3- to 8-fold. Analyses showed a well-defined interaction between the kinetic variables of membrane voltage, pHo and [NO3-]o. At a constant pHo of 6.1, depolarization from -250 to -150 mV resulted in an approximate 3-fold reduction in the maximum current but a 10% rise in the apparent affinity for NO3-. By contrast, the same depolarization effected an approximate 20% fall in the Km for transport as a function in [H+]o. These, and additional characteristics of the transport current implicate a carrier cycle in which NO3-binding is kinetically isolated from the rate-limiting step of membrane charge transit, and they indicate a charge-coupling stoichiometry of 2(H+) per NO3-anion transported across the membrane. The results concur with previous studies showing a high-affinity NO3-transport system in Arabidopsis that is inducible following a period of nitrogen-limiting growth, but they underline the importance of voltage as a kinetic factor controlling NO3-transport at the plant plasma membrane. © 1995 Springer-Verlag New York Inc.
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Age-related changes in the facial expression of pain during the first 18 months of life have important implications for our understanding of pain and pain assessment. We examined facial reactions video recorded during routine immunization injections in 75 infants stratified into 2-, 4-, 6-, 12-, and 18-month age groups. Two facial coding systems differing in the amount of detail extracted were applied to the records. In addition, parents completed a brief questionnaire that assessed child temperament and provided background information. Parents' efforts to soothe the children also were described. While there were consistencies in facial displays over the age groups, there also were differences on both measures of facial activity, indicating systematic variation in the nature and severity of distress. The least pain was expressed by the 4-month age group. Temperament was not related to the degree of pain expressed. Systematic variations in parental soothing behaviour indicated accommodation to the age of the child. Reasons for the differing patterns of facial activity are examined, with attention paid to the development of inhibitory mechanisms and the role of negative emotions such as anger and anxiety.
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Objective: The ability of families to assume caregiving responsibilities is contingent on material, social, and professional support. Inadequate or inappropriate support to the terminally ill and their family caregivers can result in the misuse of resources and add burden to the family. In this report, we describe service preferences among informal caregivers of the terminally ill. Design: Three hundred seventy-three caregivers participated in telephone interviews at two points in time: when the terminally ill person was designated as palliative and 5 months subsequent to the first interview. In the case that the care recipient died during the study period, the caregiver participated in the interview three months after the death. Measures: After reviewing possible services received by the care recipients and caregivers, caregivers were asked to identify the five services they found most valuable and which services they would have liked to have had or received more of when caregiving. Results: The five services caregivers reported as most valuable included: in-home nursing care, (90.7%); family physicians, (45.6%); medical specialists, (46.4%); housekeeping, (23.6%); and, religious support, (11.3%). The five most frequently reported services that family caregivers would have liked to have received or had more available included: housekeeping, (13.1%); caregiver respite, (10.2%); in-home nursing care, (8.0%); personal support workers, (4.6%); and, self-help/support groups, (3.8%). Analyses revealed that most (64.8%) perceived service needs were of a supportive nature for caregivers. Caregiver perceptions of the value and perceived need of services were consistent over time and into bereavement. Logistic regression analyses suggested that younger caregivers who were not employed, reported higher levels of burden and cared for someone with a diagnosis of cancer had greater perceived service needs. Conclusions: The findings reported in this paper provide important insights into caregiver perceptions of valued services when caring for a terminally ill family member. These finding also highlight the stability of caregiver service perceptions over time and into bereavement.
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Aims. To evaluate the intraocular pressure (IOP) measurements in patients with band keratopathy or glued corneas obtained from affected and non-affected areas. Methods. 15 patients with band keratopathy or glued corneas were prospectively recruited. When both eyes were affected, only the right eye was analysed. Tono-Pen readings of IOP were obtained sequentially from the affected and non-affected corneal surface. Additionally, Goldmann applanation tonometry was attempted. Results. Determination of IOP with the Tono-Pen was possible in all cases, while Goldmann tonometry was not performed in three patients because of severe corneal irregularities. The average of the Tono-Pen readings obtained from the affected cornea (34.8 (SD 14.0) mmHg) was consistently and significantly higher (p <0.001) than mean IOP obtained by the Tono-Pen from the non-affected area (14.8 (4.3) mmHg). The average of Goldmann tonometry readings (14.4 (6.1) mmHg) did not differ significantly from the Tono-Pen values obtained from the non-affected corneal area (p = 0.47) but was significantly lower than the Tono-Pen measurements obtained from the affected area (p <0.001) Conclusion. In patients with band keratopathy or glued corneas determination of IOP by Tono-Pen tonometry varies from affected to non-affected area. The Tono-Pen overestimates the level of IOP when it is applied to areas with band keratopathy or with glue.
Resumo:
Optically active S-alkyl-N, N'-bis((S)-1-phenylethyl) thiouronium salts, abbreviated as (S)-[Cnpetu] Y (where Y is an anion; n = 1, 2, 3, 4, 6, 8, 10, 12 or 16), have been prepared and studied by a broad spectrum of analyses. This consists of density, viscosity, and conductivity determination, followed by a discussion of relevant correlations. Unusual trends depending on the S-alkyl chain length were documented for (S)-[Cnpetu][ NTf2] series (where [NTf2] = bis{(trifluoromethyl) sulfonyl} amide), including the viscosity decreasing with increasing chain length, and the conductivity showing a maximum between the S-butyl and the S-hexyl derivative. In addition, a hindered rotamerism of the thiouronium cation in dmso-d(6) solution was recognised by H-1 and C-13 NMR techniques. Thorough analysis of NMR spectra confirmed that the main contribution comes from rotation about the partial double C-S bond. For the first time, a neat thiouronium ionic liquid system has been subjected to quantitative analysis of hindered rotamerism by dynamic NMR coalescence studies, with estimated activation energy for rotation of 63.9 +/- 0.4 kJ mol(-1). Finally, the application of (S)-[C(n)petu] Y salts as chiral discriminating agents for carboxylates by 1H NMR spectroscopy was further investigated, demonstrating the influence of the S-alkyl chain length on chiral recognition; (S)-[C(2)petu][NTf2] ionic liquid with the mandelate anion gave the best results.
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RATIONALE: Risk of infection with Pseudomonas aeruginosa in cystic fibrosis (CF) may be associated with environmental factors.
OBJECTIVES: To determine whether residential location is associated with risk of first acquisition of P. aeruginosa.
METHODS: We performed bronchoalveolar lavage and upper airway cultures in children newly diagnosed with CF to identify infection with P. aeruginosa during infancy and early childhood. Children were assessed according to their residence in a regional or metropolitan area. Multilocus sequence typing was used to determine P. aeruginosa genotype. An environmental questionnaire was also administered.
MEASUREMENTS AND MAIN RESULTS: A total of 105 of 120 (87.5%) infants diagnosed with CF were included in this study. Diagnosis in 65 infants (61.9%) followed newborn screening at mean age of 4.6 weeks. Sixty subjects (57.1%) were homozygous ΔF508, and 47 (44.8%) were female. Fifty-five (52.3%) infants were regional, of whom 26 (47.3%), compared with 9 of 50 (18.0%) metropolitan children, acquired infection with P. aeruginosa (odds ratio, 4.084; 95% confidence interval, 1.55-11.30). Age at acquisition was similar (regional: median, 2.31 yr; range, 0.27-5.96 yr; metropolitan: median, 3.10 yr, range, 0.89-3.70 yr). Strain typing identified P. aeruginosa genotypes often encountered in different ecological settings and little evidence of cross-infection. Ninety questionnaires (85.7%) were completed. Those who acquired P. aeruginosa were more likely to be living in a household that used water sprinkler systems (P = 0.032), but no differences were identified to explain increased risk of acquisition of P. aeruginosa in regional children.
CONCLUSIONS: Geographical difference in residence of children with CF was associated with increased risk of first acquisition of P. aeruginosa, usually with strains associated with the environment rather than with cross-infection.
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Ultrasound has long been recognized as a means of effecting change at the cellular and tissue levels [1-3], which may be enhanced in the presence of photosensitive agents [4-6]. During insonation, the presence of bubbles can also play a role, creating strong microstreaming effects in solution and in more dramatic circumstances leading to the formation of energetic microjets [7], plasmas [8], and the production of other highly reactive species [9]. Such sonodynamic activity has generated particular excitement in the medical community as it Moreover the dual role for microbubbles as both an adjunct to therapy and a diagnostic echogenicity enhancer has seen industry take a proactive role in their development. In the present paper we studied the role of ultrasound driven sonoluminescent light on the degradation of a fluorescent test species (rhodamine) in the presence of an archetypal photocatalyst material, TiO 2, with a view to exploring its exploitation potential for downstream medical applications. We found that, whilst the efficiency of this process is seen to be low compared with conventional ultra-violet sources, we advocate the further exploration of the sonoluminescent approach given its potential for non-invasive applications. A strategy for enhancing the effect is also suggested.
Resumo:
BACKGROUND: Acute promyelocytic leukaemia is a chemotherapy-sensitive subgroup of acute myeloid leukaemia characterised by the presence of the PML-RARA fusion transcript. The present standard of care, chemotherapy and all-trans retinoic acid (ATRA), results in a high proportion of patients being cured. In this study, we compare a chemotherapy-free ATRA and arsenic trioxide treatment regimen with the standard chemotherapy-based regimen (ATRA and idarubicin) in both high-risk and low-risk patients with acute promyelocytic leukaemia.
METHODS: In the randomised, controlled, multicentre, AML17 trial, eligible patients (aged ≥16 years) with acute promyelocytic leukaemia, confirmed by the presence of the PML-RARA transcript and without significant cardiac or pulmonary comorbidities or active malignancy, and who were not pregnant or breastfeeding, were enrolled from 81 UK hospitals and randomised 1:1 to receive treatment with ATRA and arsenic trioxide or ATRA and idarubicin. ATRA was given to participants in both groups in a daily divided oral dose of 45 mg/m(2) until remission, or until day 60, and then in a 2 weeks on-2 weeks off schedule. In the ATRA and idarubicin group, idarubicin was given intravenously at 12 mg/m(2) on days 2, 4, 6, and 8 of course 1, and then at 5 mg/m(2) on days 1-4 of course 2; mitoxantrone at 10 mg/m(2) on days 1-4 of course 3, and idarubicin at 12 mg/m(2) on day 1 of the final (fourth) course. In the ATRA and arsenic trioxide group, arsenic trioxide was given intravenously at 0·3 mg/kg on days 1-5 of each course, and at 0·25 mg/kg twice weekly in weeks 2-8 of course 1 and weeks 2-4 of courses 2-5. High-risk patients (those presenting with a white blood cell count >10 × 10(9) cells per L) could receive an initial dose of the immunoconjugate gemtuzumab ozogamicin (6 mg/m(2) intravenously). Neither maintenance treatment nor CNS prophylaxis was given to patients in either group. All patients were monitored by real-time quantitative PCR. Allocation was by central computer minimisation, stratified by age, performance status, and de-novo versus secondary disease. The primary endpoint was quality of life on the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 global health status. All analyses are by intention to treat. This trial is registered with the ISRCTN registry, number ISRCTN55675535.
FINDINGS: Between May 8, 2009, and Oct 3, 2013, 235 patients were enrolled and randomly assigned to ATRA and idarubicin (n=119) or ATRA and arsenic trioxide (n=116). Participants had a median age of 47 years (range 16-77; IQR 33-58) and included 57 high-risk patients. Quality of life did not differ significantly between the treatment groups (EORTC QLQ-C30 global functioning effect size 2·17 [95% CI -2·79 to 7·12; p=0·39]). Overall, 57 patients in the ATRA and idarubicin group and 40 patients in the ATRA and arsenic trioxide group reported grade 3-4 toxicities. After course 1 of treatment, grade 3-4 alopecia was reported in 23 (23%) of 98 patients in the ATRA and idarubicin group versus 5 (5%) of 95 in the ATRA and arsenic trioxide group, raised liver alanine transaminase in 11 (10%) of 108 versus 27 (25%) of 109, oral toxicity in 22 (19%) of 115 versus one (1%) of 109. After course 2 of treatment, grade 3-4 alopecia was reported in 25 (28%) of 89 patients in the ATRA and idarubicin group versus 2 (3%) of 77 in the ATRA and arsenic trioxide group; no other toxicities reached the 10% level. Patients in the ATRA and arsenic trioxide group had significantly less requirement for most aspects of supportive care than did those in the ATRA and idarubicin group.
INTERPRETATION: ATRA and arsenic trioxide is a feasible treatment in low-risk and high-risk patients with acute promyelocytic leukaemia, with a high cure rate and less relapse than, and survival not different to, ATRA and idarubicin, with a low incidence of liver toxicity. However, no improvement in quality of life was seen.
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Response surface methodology was used to develop models to predict the effect of tomato cultivar, juice pH, blanching temperature and time on colour change of tomato juice after blanching. The juice from three tomato cultivars with adjusted pH levels ranging from 3.9 to 4.6 were blanched at temperatures from 60-100 °C for 1-5 min using the central composite design (CCD). The colour change was assessed by calculating the redness (a/b) and total colour change (∆E) after measuring the Hunter L, a and b values. Developed models for both redness and ∆E were significant (p<0.0001) with satisfactory coefficient of determination (R2 = 0.99 and 0.97) and low coefficient of variation (CV% = 1.89 and 7.23), respectively. Multilevel validation that was implemented revealed that the variation between the predicted and experimental values obtained for redness and ∆E were within the acceptable error range of 7.3 and 22.4%, respectively
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By contrast to the Target Normal Sheath acceleration (TNSA) mechanism [1], Radiation Pressure Acceleration (RPA) is currently attracting a substantial amount of experimental [2,3] and theoretical [4-6] attention worldwide due to its superior scaling in terms of ion energy and laser-ion conversion efficiency. Employing Vulcan Petawatt lasers of the Rutherford Appleton Laboratory, UK, both the Hole-boring (HB) and the Light-Sail (LS) regimes of the RPA have been extensively explored. When the target thickness is of the order of hole-boring velocity times the laser pulse duration, highly collimated plasma jets of near solid density are ejected from the foil, lasting up to ns after the laser interaction. By changing the linear polarisation of the laser to circular, improved homogeneity in the jet's spatial density profile is achieved which suggests more uniform and sustained radiation pressure drive on target ions. By decreasing the target areal density or increasing irradiance on the target, the LS regime of the RPA is accessed where relatively high flux (~ 1012 particles/MeV/Sr) of ions are accelerated to ~ 10 MeV/nucleon energies in a narrow energy bandwidth. The ion energy scaling obtained from the parametric scans agrees well with theoretical estimation based on RPA mechanism and the narrow bandwidth feature in the ion spectra is studied by 2D particle-in-simulations.
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BACKGROUND: In sub-Saharan Africa, where infectious diseases and nutritional deficiencies are common, severe anaemia is a common cause of paediatric hospital admission, yet the evidence to support current treatment recommendations is limited. To avert overuse of blood products, the World Health Organisation advocates a conservative transfusion policy and recommends iron, folate and anti-helminthics at discharge. Outcomes are unsatisfactory with high rates of in-hospital mortality (9-10 %), 6-month mortality and relapse (6 %). A definitive trial to establish best transfusion and treatment strategies to prevent both early and delayed mortality and relapse is warranted.
METHODS/DESIGN: TRACT is a multicentre randomised controlled trial of 3954 children aged 2 months to 12 years admitted to hospital with severe anaemia (haemoglobin < 6 g/dl). Children will be enrolled over 2 years in 4 centres in Uganda and Malawi and followed for 6 months. The trial will simultaneously evaluate (in a factorial trial with a 3 x 2 x 2 design) 3 ways to reduce short-term and longer-term mortality and morbidity following admission to hospital with severe anaemia in African children. The trial will compare: (i) R1: liberal transfusion (30 ml/kg whole blood) versus conservative transfusion (20 ml/kg) versus no transfusion (control). The control is only for children with uncomplicated severe anaemia (haemoglobin 4-6 g/dl); (ii) R2: post-discharge multi-vitamin multi-mineral supplementation (including folate and iron) versus routine care (folate and iron) for 3 months; (iii) R3: post-discharge cotrimoxazole prophylaxis for 3 months versus no prophylaxis. All randomisations are open. Enrolment to the trial started September 2014 and is currently ongoing. Primary outcome is cumulative mortality to 4 weeks for the transfusion strategy comparisons, and to 6 months for the nutritional support/antibiotic prophylaxis comparisons. Secondary outcomes include mortality, morbidity (haematological correction, nutritional and infectious), safety and cost-effectiveness.
DISCUSSION: If confirmed by the trial, a cheap and widely available 'bundle' of effective interventions, directed at immediate and downstream consequences of severe anaemia, could lead to substantial reductions in mortality in a substantial number of African children hospitalised with severe anaemia every year, if widely implemented.
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Double photoionization accompanied by loss of n C atoms (n=0, 2, 4, 6) was investigated by merging beams of Xe@C60+ ions and synchrotron radiation and measuring the yields of product ions. The giant 4d dipole resonance of the caged Xe atom has a prominent signature in the cross section for these product channels, which together account for 6.2 ± 1.4 of the total Xe 4d oscillator strength of 10. Compared to that for a free Xe atom, the oscillator strength is redistributed in photon energy due to multipath interference of outgoing Xe 4d photoelectron waves that may be transmitted or reflected by the spherical C60+ molecular cage, yielding so-called confinement resonances. The data are compared with an earlier measurement and with theoretical predictions for this single-molecule photoelectron interferometer system. Relativistic R-matrix calculations for the Xe atom in a spherical potential shell representing the fullerene cage show the sensitivity of the interference pattern to the molecular geometry. © 2013 American Physical Society.
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Effective collision strengths for electron-impact excitation of the N-like ion NeIV are calculated in the close-coupling approximation using the multichannel R-matrix method. Specific attention is given to the 10 astrophysically important fine-structure forbidden transitions among the 4So, 2Do and 2Po levels in the 2s22p3 ground-state configuration. The expansion of the total wavefunction incorporates the lowest 11 LS eigenstates of NeIV, consisting of eight n = 2 terms with configurations 2s22p3, 2s2p4 and 2p5, together with three n = 3 states of configuration 2s22p23s. We present in graphical form the effective collision strengths obtained by thermally averaging the collision strengths over a Maxwellian distribution of velocities, for all 10 fine-structure transitions, over the range of electron temperatures log T(K) = 3.6 to log T(K) = 6.1 (the range appropriate for astrophysical applications). Comparisons are made with the earlier, less sophisticated close-coupling calculation of Giles, and excellent agreement is found in the limited temperature region where a comparison is possible [log T(K) = 3.7 to log 7(K) = 4.3]. At higher temperatures the present data are the only reliable results currently available.