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1.
Philos Trans A Math Phys Eng Sci ; 379(2189): 20200022, 2021 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-33280560

RESUMEN

When high-energy and high-power lasers interact with matter, a significant part of the incoming laser energy is transformed into transient electromagnetic pulses (EMPs) in the range of radiofrequencies and microwaves. These fields can reach high intensities and can potentially represent a significative danger for the electronic devices placed near the interaction point. Thus, the comprehension of the origin of these electromagnetic fields and of their distribution is of primary importance for the safe operation of high-power and high-energy laser facilities, but also for the possible use of these high fields in several promising applications. A recognized main source of EMPs is the target positive charging caused by the fast-electron emission due to laser-plasma interactions. The fast charging induces high neutralization currents from the conductive walls of the vacuum chamber through the target holder. However, other mechanisms related to the laser-target interaction are also capable of generating intense electromagnetic fields. Several possible sources of EMPs are discussed here and compared for high-energy and high-intensity laser-matter interactions, typical for inertial confinement fusion and laser-plasma acceleration. The possible effects on the electromagnetic field distribution within the experimental chamber, due to particle beams and plasma emitted from the target, are also described. This article is part of a discussion meeting issue 'Prospects for high gain inertial fusion energy (part 2)'.

2.
Opt Lett ; 45(19): 5575-5578, 2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-33001957

RESUMEN

The interaction of an ultra-intense laser with a solid state target allows the production of multi-MeV proton and ion beams. This process is explained by the target normal sheath acceleration (TNSA) model, predicting the creation of an electric field on the target rear side, due to an unbalanced positive charge. This process is related to the emission of relativistic ultrafast electrons, occurring at an earlier time. In this work, we highlight the correlations between the ultrafast electron component and the protons by their simultaneous detection by means of an electro-optical sampling and a time-of-flight diagnostics, respectively, supported by numerical simulations showing an excellent agreement.

3.
Int Endod J ; 52(9): 1388-1396, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30982994

RESUMEN

AIM: To determine the knowledge of final year undergraduate students attending Italian universities on the appropriate use of systemic antibiotics for endodontic infections. METHODOLOGY: Final year dental students from twenty Italian universities completed a one-page questionnaire on antibiotic use for the treatment of endodontic infections. Data were analysed using descriptive statistics and chi-square tests. RESULTS: A total of three hundred and three students completed the questionnaire. The average duration of antibiotic prescription proposed by respondents was 5.48 ± 1.06 days. Amoxicillin with clavulanic acid was the first-choice antibiotic (85.2%) followed by amoxicillin alone (13.5%), azithromycin (1.0%) and clarithromycin (0.3%), for patients not allergic to penicillin. Clarithromycin was the first-choice drug for patients with a penicillin allergy (56.1%), followed from azithromycin (31.7%), clindamycin (11.9%) and levofloxacin (0.3%). Alveolar abscess with systemic manifestations was reported as the principal reason to prescribe antibiotics (97.7%) followed by the same condition without systemic manifestations (85.5%). For the scenario of irreversible pulpitis, 5% of students considered antibiotics necessary. Almost 52% of students would prescribe antibiotics for apical acute periodontitis; 29.7% would prescribe antibiotics for chronic apical periodontitis with sinus tract, and 13.5% indicated these drugs for chronic apical periodontitis without sinus tract. CONCLUSIONS: The results demonstrate that it is necessary to improve the knowledge of Italian students on antibiotics and indications for their use in endodontics.


Asunto(s)
Antibacterianos , Estudiantes de Odontología , Humanos , Italia , Pautas de la Práctica en Odontología , Encuestas y Cuestionarios
4.
J Vet Pharmacol Ther ; 40(5): 468-475, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27925221

RESUMEN

Grapiprant is the novel selective EP4 receptor inhibitor recently issued on the veterinary market for dogs affected by osteoarthritis. The aim of this study was twofold: to evaluate the pharmacokinetics and the pharmacodynamics of grapiprant in the induced inflammatory pain model in the rabbit after a single IV injection of 2 mg/kg; to compare the thermal antinociception effect after 2 mg/kg IV grapiprant, with that generated by 0.5 mg/kg meloxicam SC injected. Rabbits (n = 12) were randomly assigned to two crossover studies (single-dose, two-period crossover). The first study group A (n = 3) received a single IV dose of grapiprant at 2 mg/kg dissolved in ethanol. Group B (n = 3) received a single IV injection of ethanol (equivalent volume to grapiprant volume) at the same site. The second study group C (n = 3) received a single SC dose of meloxicam at 0.5 mg/kg. Group D (n = 3) received a single SC injection of 15% ethanol (equivalent volume to grapiprant volume) at the same site. After a 2-week washout period, the groups were rotated and the experiments repeated. Blood samples (0.7 mL) were collected from the right ear artery at assigned times and grapiprant plasma concentrations determined by a validated HPLC-FL method. Three hours prior to administration of the drugs, inflammation was induced by SC injection of lambda carrageenan (200 µL, 3% in physiological saline) under the plantar surface of the right hind paw. At a similar time to the blood collection, an infrared thermal stimuli (40 °C) was applied to the plantar surface of the rabbits' hindlimbs to evaluate the thermal withdrawal latency (TWL). The thermal antinociceptive effect was expressed as maximum possible response (% MPR). Grapiprant plasma concentrations were detectable up to the 10-h time point (concentration range 17-7495 ng/mL). The grapiprant-treated group showed a significant increase in TWL from 1 h and up to 10 h after drug administration compared to the control. In contrast, the meloxicam group showed a significant increase in TWL from 4 up to 10 h after drug administration, compared to control. The maximal MPR% was not statistically different between the grapiprant and meloxicam group from 4 to 8 h, while significant differences were shown at 1, 1.5, 2, 10 and 24 h. Given these findings, grapiprant appears to be an attractive option for antinociception in rabbits, due to its rapid onset and extended duration of effect.


Asunto(s)
Osteoartritis/veterinaria , Dolor/veterinaria , Compuestos de Sulfonilurea/farmacocinética , Animales , Carragenina/administración & dosificación , Estudios Cruzados , Modelos Animales de Enfermedad , Perros , Osteoartritis/inducido químicamente , Osteoartritis/tratamiento farmacológico , Dolor/inducido químicamente , Dolor/tratamiento farmacológico , Conejos , Distribución Aleatoria , Compuestos de Sulfonilurea/farmacología , Resultado del Tratamiento
5.
J Vet Pharmacol Ther ; 40(1): 62-69, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27121980

RESUMEN

Enrofloxacin (E) is commonly used in veterinary medicine. It is necessary to perform pharmacokinetic/dynamic studies to minimize the selection of resistant mutants of bacteria and extend the efficacy of antimicrobial agents. Eight healthy adult Pogona vitticeps were assigned into two groups of equal size and treated with a single intramuscular injection of E at 10 mg/kg. Blood samples were withdrawn at different scheduled times for each group, and rectal swabs were collected. E and ciprofloxacin (active metabolite) blood concentrations were quantified by an HPLC validated method, while the in vitro antimicrobial susceptibility was evaluated by the Kirby-Bauer disc diffusion susceptibility test. The pharmacokinetic profiles of E gave similar pharmacokinetic parameters irrespective of the collection time schedule. Bacteria isolation showed the presence of both E. coli, Salmonella enterica subspecies enterica and subspecies 3a, Proteus spp., and Pseudomonas spp. The majority of isolated colonies were sensitive to E, but the treatment did not reduce the number of bacteria in faeces. Results suggest that E is able to reach blood concentrations high enough to kill susceptible bacteria (MIC < 0.9 µg/mL), but at the same time does not significantly affect intestinal bacteria.


Asunto(s)
Antibacterianos/farmacocinética , Fluoroquinolonas/farmacocinética , Lagartos/metabolismo , Animales , Antibacterianos/administración & dosificación , Antibacterianos/sangre , Antibacterianos/farmacología , Cromatografía Líquida de Alta Presión/veterinaria , Ciprofloxacina/sangre , Enrofloxacina , Escherichia coli/efectos de los fármacos , Femenino , Fluoroquinolonas/administración & dosificación , Fluoroquinolonas/sangre , Fluoroquinolonas/farmacología , Inyecciones Intramusculares/veterinaria , Lagartos/sangre , Masculino , Pruebas de Sensibilidad Microbiana/veterinaria , Proteus/efectos de los fármacos , Pseudomonas/efectos de los fármacos , Salmonella enterica/efectos de los fármacos
6.
J Vet Pharmacol Ther ; 38(5): 488-96, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25623330

RESUMEN

In reptiles, administration of opioid drugs has yielded unexpected results with respect to analgesia. The aims of this study were to assess the pharmacokinetic/pharmacodynamic (PK/PD) properties of tramadol and its active metabolite M1 and to evaluate the effect of the renal portal system on the PK/PD parameters in yellow-bellied slider turtles. Turtles (n = 19) were randomly assigned to four treatment groups, according to a masked, single-dose, four-treatment, unpaired, four-period crossover design. Group A (n = 5) received a single i.m. dose of tramadol (50 mg/mL) at 10 mg/kg in the proximal hindlimb. Group B (n = 5) received the same i.m. dose but in the forelimb. Groups C (n = 5) and D (n = 4) received a single i.m. injection of saline (NaCl 0.9%) of equivalent volume to the volumes of tramadol injected in the hind- and forelimb, respectively. Groups were rotated (1-month washout period) until the completion of the crossover study. Tramadol plasma concentrations were evaluated by a validated HPLC-FL method. An infrared thermal stimulus was applied to the plantar surface of the turtles' hindlimbs to evaluate the thermal withdrawal latency (TWL). The two PK profiles of tramadol differed in the first 2 h following administration, but overlapped in the elimination phases. The metabolite M1 was formed in both the treatment groups, showing similar pharmacokinetic trends, although the amount of M1 was significantly higher (20%) in the hindlimb vs. forelimb group. Turtles given tramadol in the hind- and forelimb showed a significant increase in TWL over the periods of 0.5-48 and 8-48 h, respectively. The calculated % maximal possible response (% MPR) was low (about 24%). The PK/PD correlations between M1 plasma concentrations vs. % MPR appeared to show a counterclockwise hysteresis loop shape.


Asunto(s)
Analgésicos Opioides/farmacocinética , Tramadol/farmacocinética , Tortugas/metabolismo , Analgésicos Opioides/administración & dosificación , Analgésicos Opioides/sangre , Animales , Femenino , Miembro Anterior , Miembro Posterior , Inyecciones Intramusculares/veterinaria , Masculino , Tramadol/administración & dosificación , Tramadol/sangre , Tortugas/sangre
7.
Curr Oncol ; 20(4): 212-9, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23904762

RESUMEN

BACKGROUND: Sexually transmitted infection with the human papillomavirus (hpv) is responsible for a significant burden of human cancers involving the cervix, anogenital tract, and oropharynx. Studies in the United States and Europe have demonstrated an alarming increase in the frequency of hpv-positive oropharyngeal cancer, but the same direct evidence does not exist in Canada. METHODS: Using the London Health Sciences Centre pathology database, we identified tonsillar cancers diagnosed between 1993 and 2011. Real-time polymerase chain reaction was then used on pre-treatment primary-site biopsy samples to test for dna from the high-risk hpv types 16 and 18. The study cohort was divided into three time periods: 1993-1999, 2000-2005, and 2006-2011. RESULTS: Of 160 tumour samples identified, 91 (57%) were positive for hpv 16. The total number of tonsillar cancers significantly increased from 1993-1999 to 2006-2011 (32 vs. 68), and the proportion of cases that were hpv-positive substantially increased (25% vs. 62%, p < 0.002). Those changes were associated with a marked improvement in 5-year overall survival (39% in 1993-1999 vs. 84% in 2006-2011, p < 0.001). When all factors were included in a multivariable model, only hpv status predicted treatment outcome. INTERPRETATION: The present study is the first to provide direct evidence that hpv-related oropharyngeal cancer is increasing in incidence in a Canadian population. Given the long lag time between hpv infection and clinically apparent malignancy, oropharyngeal cancer will be a significant clinical problem for the foreseeable future despite vaccination efforts.

8.
Braz J Biol ; 83: e271785, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37610945

RESUMEN

Ortho-eugenol is a synthetic derivative from eugenol, the major compound of clove essential oil, which has demonstrated antidepressant and antinociceptive effects in pioneering studies. Additionally, its effects appear to be dependent on the noradrenergic and dopaminergic systems. Depression and anxiety disorders are known to share a great overlap in their pathophysiology, and many drugs are effective in the treatment of both diseases. Furthermore, high levels of anxiety are related to working memory deficits and increased oxidative stress. Thus, in this study we investigated the effects of acute treatment of ortho-eugenol, at 50, 75 and 100 mg/kg, on anxiety, working memory and oxidative stress in male Swiss mice. Our results show that the 100 mg/kg dose increased the number of head-dips and reduced the latency in the hole-board test. The 50 mg/kg dose reduced malondialdehyde levels in the prefrontal cortex and the number of Y-maze entries compared to the MK-801-induced hyperlocomotion group. All doses reduced nitrite levels in the hippocampus. It was also possible to assess a statistical correlation between the reduction of oxidative stress and hyperlocomotion after the administration of ortho-eugenol. However, acute treatment was not able to prevent working memory deficits. Therefore, the present study shows that ortho-eugenol has an anxiolytic and antioxidant effect, and was able to prevent substance-induced hyperlocomotion. Our results contribute to the elucidation of the pharmacological profile of ortho-eugenol, as well as to direct further studies that seek to investigate its possible clinical applications.


Asunto(s)
Eugenol , Memoria a Corto Plazo , Masculino , Animales , Ratones , Eugenol/farmacología , Eugenol/uso terapéutico , Ansiedad/tratamiento farmacológico , Trastornos de Ansiedad , Estrés Oxidativo , Trastornos de la Memoria/inducido químicamente , Trastornos de la Memoria/tratamiento farmacológico , Aceite de Clavo
9.
Braz J Biol ; 83: e271781, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37255202

RESUMEN

Due to the complex nature of pain and the participation of physical, cognitive, psychological and behavioral aspects, pain management has several approaches. The use of medicinal plants in developing countries is quite expressive. Seeking new options for the treatment of emerging or debilitating diseases. Therefore, the present study seeks to elucidate the effects of the monoterpene, citronellal, differentiating its activity by isomers (R)-(+) and (S)-(-) citronellal. The study used several methods to evaluate the effects of citronellal isomers on motor coordination, nociceptive response, and the involvement of opioid, glutamatergic, and transient receptor pathways. The methods included rota-rod, hot-plate, and formalin tests, as well as the use of specific inhibitors and agonists. Data were analyzed using inferential statistics with a 95% confidence level. Both isomers did not significantly affect the motor coordination of the studied animals. The isomer (S)-(-) citronellal showed better results in relation to its structural counterpart, managing to have an antinociceptive effect in the formalin and hot plate tests with a lower concentration (100 mg/kg) and presenting fewer side effects, however, the this study was not able to elucidate the mechanism of action of this isomer despite having activity in studies with substances that act on specific targets such as glutamate and capsaicin, its activity was not reversed with the use of antagonists for pathways related to nociception. While the (R)-(+) citronellal isomer, despite showing total activity only at a concentration of 150 mg/kg, was able to determine its mechanism of action related to the opioid pathway by reversing its activity by the antagonist naloxone, being this is a pathway already correlated with nociception control treatments, however, it is also related to some unwanted side effects. In this way, new studies are sought to elucidate the mechanism related to the isomer (S)-(-) citronellal and a possibility of use in other areas related to the treatment of pain or inflammation.


Asunto(s)
Analgésicos , Monoterpenos , Animales , Analgésicos/farmacología , Analgésicos/uso terapéutico , Monoterpenos/farmacología , Monoterpenos/uso terapéutico , Analgésicos Opioides/uso terapéutico , Dolor/tratamiento farmacológico , Extractos Vegetales/química
10.
Epidemiol Infect ; 140(4): 633-42, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21733246

RESUMEN

To determine whether drinking water contaminated with antimicrobial-resistant E. coli is associated with the carriage of resistant E. coli, selected households sending water samples to Ontario and Alberta laboratories in 2005-2006 were asked to participate in a cross-sectional study. Household members aged ≥12 years were asked to complete a questionnaire and to submit a rectal swab. In 878 individuals, 41% carried a resistant strain of E. coli and 28% carried a multidrug-resistant strain. The risk of carriage of resistant E. coli was 1·26 times higher for users of water contaminated with resistant E. coli. Other risk factors included international travel [prevalence ratio (PR) 1·33], having a child in nappies (PR 1·33), being male (PR 1·33), and frequent handling of raw red meats (PR 1·10). Protecting private water sources (e.g. by improving systems to test and treat them) may help slow the emergence of antimicrobial resistance in E. coli.


Asunto(s)
Agua Potable/microbiología , Infecciones por Escherichia coli/transmisión , Escherichia coli , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Alberta/epidemiología , Niño , Estudios Transversales , Farmacorresistencia Bacteriana , Escherichia coli/efectos de los fármacos , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/etiología , Composición Familiar , Heces/microbiología , Femenino , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Ontario/epidemiología , Prevalencia , Adulto Joven
11.
J Laryngol Otol ; 136(3): 243-247, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34602108

RESUMEN

OBJECTIVE: To determine the prevalence of human papillomavirus in paediatric tonsils in Southwestern Ontario, Canada. MATERIALS AND METHODS: Patients aged 0-18 years undergoing tonsillectomy were recruited. Two specimens (left and right tonsils) were collected from each participant. Tonsillar DNA was analysed using quantitative polymerase chain reaction to determine the presence of human papillomavirus subtypes 6, 11, 16 or 18. RESULTS: A total of 102 patients, aged 1-18 years (mean age of 5.7 years), were recruited. Ninety-nine surveys were returned. There were 44 females (44.4 per cent) and 55 males (55.6 per cent). Forty patients (40.4 per cent) were firstborn children and 73 (73.7 per cent) were delivered vaginally. Six mothers (6.1 per cent) and one father (1.0 per cent) had prior known human papillomavirus infection, and one mother (1.0 per cent) had a history of cervical cancer. All tonsil specimens were negative for human papillomavirus subtypes 6, 11, 16 and 18. CONCLUSION: No human papillomavirus subtypes 6, 11, 16 or 18 were found in paediatric tonsil specimens from Southwestern Ontario.


Asunto(s)
Alphapapillomavirus/aislamiento & purificación , Tonsila Palatina/virología , Infecciones por Papillomavirus/epidemiología , Síndromes de la Apnea del Sueño/virología , Tonsilitis/virología , Adolescente , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Ontario , Prevalencia , Síndromes de la Apnea del Sueño/cirugía , Tonsilectomía , Tonsilitis/cirugía
12.
Clin Nephrol ; 75(5): 440-50, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21543024

RESUMEN

BACKGROUND: Venous thromboembolism (VTE) is one of the thrombotic complications that occur in renal transplant recipients (RTR). The observation that vitamin D receptor activators, angiotensin-converting enzyme inhibitors (ACEi), and angiotensin receptor blockers (ARBs) have a protective effect against protrombotic state suggests that their possible combination could reduce the incidence of VTE in RTR. OBJECTIVES: to evaluate the incidence of VTE in RTR and the timing of occurrence after renal transplantation (Tx); to compare the incidence of VTE in our RTR and RTR on calcitriol, ACEi, ARBs and their combination therapy. Risk factors were also evaluated. RESULTS: During follow-up, 96 of 769 RTRs, 73 males 23 females, developed a first episode of VTE: 23 in the first 3 months after Tx; 15 from 3 to 6 months; 9 from 6 to 12 months; 13 from 12 to 48 months and 36 after more than 48 months. The incidence was significantly lower in RTR on treatment with a combination of calcitriol 0.25 µg/day, an ACEi and an ARB and in RTR on treatment with only calcitriol 0.5 µg/day (9.4% and 9%, respectively, vs. 14.5% (p < 0.05)). However, the most decreased rate (5.6% vs. 14.5% (p < 0.01)) was in patients treated with a combination of calcitriol 0.5 µg/day, an ACEi and an ARB. CONCLUSION: A combination therapy with calcitriol 0.5 µg/day, ACEi, and ARB is associated with a 60% lower rate risk of VTE.


Asunto(s)
Antagonistas de Receptores de Angiotensina/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Calcitriol/uso terapéutico , Trasplante de Riñón/efectos adversos , Trombosis de la Vena/prevención & control , Adolescente , Adulto , Anciano , Antagonistas de Receptores de Angiotensina/administración & dosificación , Inhibidores de la Enzima Convertidora de Angiotensina/administración & dosificación , Calcitriol/administración & dosificación , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Trombosis de la Vena/epidemiología
14.
Sci Rep ; 11(1): 2226, 2021 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-33500441

RESUMEN

Laser-driven proton acceleration is a growing field of interest in the high-power laser community. One of the big challenges related to the most routinely used laser-driven ion acceleration mechanism, Target-Normal Sheath Acceleration (TNSA), is to enhance the laser-to-proton energy transfer such as to maximize the proton kinetic energy and number. A way to achieve this is using nanostructured target surfaces in the laser-matter interaction. In this paper, we show that nanowire structures can increase the maximum proton energy by a factor of two, triple the proton temperature and boost the proton numbers, in a campaign performed on the ultra-high contrast 10 TW laser at the Lund Laser Center (LLC). The optimal nanowire length, generating maximum proton energies around 6 MeV, is around 1-2 [Formula: see text]m. This nanowire length is sufficient to form well-defined highly-absorptive NW forests and short enough to minimize the energy loss of hot electrons going through the target bulk. Results are further supported by Particle-In-Cell simulations. Systematically analyzing nanowire length, diameter and gap size, we examine the underlying physical mechanisms that are provoking the enhancement of the longitudinal accelerating electric field. The parameter scan analysis shows that optimizing the spatial gap between the nanowires leads to larger enhancement than by the nanowire diameter and length, through increased electron heating.

15.
Clin Nephrol ; 73(6): 439-45, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20497756

RESUMEN

BACKGROUND: Skin cancer (SC) is the most frequent malignancy after renal transplantation (RT), especially squamous and basal cell carcinoma. The observation that angiotensin II is a potent angiogenic and growth factor raises the possibility that blocking its effects could reduce the incidence of skin cancer. OBJECTIVES: To evaluate the incidence of keratinocyte cancer in RT recipients, the timing of occurrence of the skin events after RT; to compare the incidence of SC in our RT recipients and in RT patients on angiotensin converting enzyme inhibitors (ACEi), angiotensin receptor blockers therapy (ARBs) and their combination. Risk factors were also evaluated. RESULTS: During follow up, 52 of 565 patients (9.2%), 38 males 14 females, developed SC at a median time of 59 months (range 29 - 74) after RT. 12 of 52 patients (23%) with SC were on ACEi, ARBs therapy or their combination. The incidence was significantly lower in user patients compared to non user (5.6% and 11.4% respectively). BCC was the most frequent type of keratinocyte cancer in non users and in users. No association with incidence of BCC or SCC was observed for other classes of antihypertensive drugs (calcium antagonists, beta-blockers, alpha-blockers). CONCLUSION: This study confirms that RT patients are at high risk of SC. The use of ACEi or ARBs is associated with an approximately two-fold reduced risk of Keratinocyte cancers compared to non users in RT recipients. We did not observe an association between the incidence of SC and the use of other classes of antihypertensive drugs. Any chemoprotective effect of these agents may reflect inhibition of the growth factor activity of angiotensin II. Use of ACEi or ARBs, when this is possible, should be considered in RT patients with multiple risk factors.


Asunto(s)
Antagonistas de Receptores de Angiotensina , Inhibidores de la Enzima Convertidora de Angiotensina/administración & dosificación , Trasplante de Riñón , Receptores de Angiotensina/uso terapéutico , Neoplasias Cutáneas/prevención & control , Adolescente , Adulto , Anciano , Carcinoma de Células Escamosas/etiología , Carcinoma de Células Escamosas/prevención & control , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Factores de Riesgo , Neoplasias Cutáneas/etiología
16.
Rev Sci Instrum ; 91(10): 103303, 2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-33138598

RESUMEN

We report on the cross-calibration of Thomson Parabola (TP) and Time-of-Flight (TOF) detectors as particle diagnostics, implemented on the most recent setup of the ALLS 100 TW laser-driven ion acceleration beamline. The Microchannel Plate (MCP) used for particle detection in the TP spectrometer has been calibrated in intensity on the tandem linear accelerator at the Université de Montréal. The experimental data points of the scaling factor were obtained by performing a pixel cluster analysis of single proton impacts on the MCP. A semi-empirical model was extrapolated and fitted to the data to apply the calibration also to higher kinetic energies and to extend it to other ion species. Two TOF lines using diamond detectors, placed at +6° and -9° with respect to the target-normal axis, were benchmarked against the TP spectrometer measurements to determine the field integrals related to its electric and magnetic dispersions. The mean integral proton numbers obtained on the beamline were about 4.1 × 1011 protons/sr with a standard deviation of 15% in the central section of the spectrum around 3 MeV, hence witnessing the high repeatability of the proton bunch generation. The mean maximum energy was of 7.3 ± 0.5 MeV, well in agreement with similar other 100 TW-scale laser facilities, with the best shots reaching 9 MeV and nearly 1012 protons/sr. The used particle diagnostics are compatible with the development of a high-repetition rate targetry due to their fast online readout and are therefore a crucial step in the automation of any beamline.

17.
Clin Nephrol ; 71(4): 423-9, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19356375

RESUMEN

BACKGROUND: Hepatitis B (HBV) and hepatitis C (HCV) virus infections are major risk factors affecting long-term morbidity and mortality after renal transplantation. Hepatitis prevalence is subject to geographical variations. OBJECTIVE: To compare and analyze the geographical prevalence, risk factors and impact of HBV and HCV infection in multinational cohorts of renal transplant recipients. METHODS: From 1989 - 2002, data on 12,856 kidney transplant recipients in 37 countries were collected within the prospective MOST (Multinational Observational Study in Transplantation). Subgroup analyses of hepatitis-related prevalence, risk factors and impact were conducted on patients whose HBV and HCV status was available at time of transplantation. Countries were substratified according to population prevalence of > or = 5% HBV or > or = 10% HCV. RESULTS: The prevalence of HBV was 2.9%, of HCV 8.7% and of HBV together with HCV 0.4%. Risk factors for hepatitis infection in renal transplant recipients were long dialysis time, retransplantation and blood transfusions. At each study endpoint up to 5 years after transplantation, no significant differences in graft function were observed, although the 1-year acute rejection rate tended to be lower in HCV+ patients. At 5 years post-transplant, there were no differences between the subgroups and regions regarding infections, post-transplant diabetes mellitus or malignancies including PTLD. CONCLUSIONS: Overall, HCV infections are more prevalent than HBV. Despite large geographical differences in prevalence, HBV and HCV status did not appear to have a significant impact on renal graft function, infections, malignancies and post-transplant diabetes mellitus up to 5 years after renal transplantation throughout the MOST countries.


Asunto(s)
Hepatitis B/epidemiología , Hepatitis C/epidemiología , Trasplante de Riñón , Adulto , Femenino , Hepatitis B/transmisión , Hepatitis C/transmisión , Humanos , Masculino , Prevalencia , Estudios Prospectivos , Factores de Riesgo , Resultado del Tratamiento
18.
G Ital Nefrol ; 26(4): 478-87, 2009.
Artículo en Italiano | MEDLINE | ID: mdl-19644837

RESUMEN

We analyze and describe the epidemiology, characteristics and outcome of patients who underwent preemptive kidney transplants from living donors. The outcome of preemptive transplants from deceased donors and that of living donor transplants in patients who have started dialysis are often compared with the outcome of preemptive transplants from living donors. The causes of the better outcome of preemptive kidney transplants are analyzed here. We have examined data from large registries including the Collaborative Transplant Study, USRDS and ANZDATA registry as well as the results of single-center studies and data from developing countries. Overall, preemptive transplantation is more frequently performed with living donors. Recipients are often younger and have fewer vascular comorbidities. Also late referrals are less frequent with preemptive kidney transplantation. The data described by different studies may be discordant, but this is caused by different factors linked to the studies, as well as donor type, recipient age and residual renal function at transplant. Preemptive transplant usually has a better outcome because of the avoidance of dialysis-related comorbidities. Preemptive transplant is associated with less delayed graft function, fewer acute rejections, and better graft and patient survival rates.


Asunto(s)
Fallo Renal Crónico/prevención & control , Trasplante de Riñón , Donadores Vivos , Adulto , Femenino , Humanos , Masculino , Resultado del Tratamiento
19.
Rev Sci Instrum ; 90(8): 083301, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31472601

RESUMEN

In this work, we calibrate the newly developed EBT-XD radiochromic films (RCFs) manufactured by Gafchromictm using protons in the energy range of 4-10 MeV. Irradiation was performed on the 2 × 6 MV tandem linear accelerator located at the Université de Montréal. The RCFs were digitized using an Epson Perfection V700 flatbed scanner using both the red-green-blue and grayscale channels. The proton fluences were measured with Faraday cups calibrated in absolute terms. The linear energy transfer function within the active layer of the films was calculated using the mass stopping power tables coming from the PSTAR database from the National Institute of Standards and Technology (NIST) to allow retrieval of the deposited dose. We find that the calibration curves for 7 and 10 MeV protons are nearly equivalent. The 4 MeV calibration curves exhibit a quenching effect due to the Bragg peak that falls close to the active layer. A linearization of this energy dependence was developed using a semiempirical parametric model to allow the generation of calibration curves for any incident proton energy within the present range. Excellent correspondence (<5% dose difference for the same netOD) of the 10 MeV calibration curves was noted when compared to existing high-energy proton (148.2 MeV) calibration curves reported in the literature. Our calibration extends the range of operation of EBT-XD films to low-energy proton beam dosimetry.

20.
Sci Rep ; 9(1): 17571, 2019 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-31748679

RESUMEN

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

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