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1.
Health Place ; 87: 103248, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38631215

RESUMEN

This study aimed to evaluate the children's usage and their physical activity levels at playgrounds with (N = 4) and without (N = 4) organized sports activities, following a quasi-experimental study design. Direct observations were used to assess the playground usage and estimate the playground users' age category, sex, and physical activity intensity level. The results indicated that playgrounds with sports activities were associated with 52% more users at the time of the activities. However, this increase was only seen in boys. Furthermore, playgrounds with sport activities were not associated with different physical activity levels in children as compared to children on regular playgrounds.

2.
Rev Sci Instrum ; 95(3)2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38477653

RESUMEN

We present a compact closed-loop recycling system for noble and inert gases. It has been developed for an extreme-ultraviolet (XUV) frequency comb based on high-harmonic generation at 100 MHz repetition rate. The system collects gas injected at several bars of backing pressure through a micrometer-sized nozzle into the laser-interaction region with a differential pumping system comprising turbomolecular pumps, and subsequently compresses the gas to a pressure of up to 200 bar. By drastically reducing the waste of expensive gases such as xenon and krypton, it enables the long operation times needed for spectroscopic measurements, as well as for continuous operation of the XUV frequency comb.

3.
Nature ; 621(7980): 716-722, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37758891

RESUMEN

Einstein's general theory of relativity from 19151 remains the most successful description of gravitation. From the 1919 solar eclipse2 to the observation of gravitational waves3, the theory has passed many crucial experimental tests. However, the evolving concepts of dark matter and dark energy illustrate that there is much to be learned about the gravitating content of the universe. Singularities in the general theory of relativity and the lack of a quantum theory of gravity suggest that our picture is incomplete. It is thus prudent to explore gravity in exotic physical systems. Antimatter was unknown to Einstein in 1915. Dirac's theory4 appeared in 1928; the positron was observed5 in 1932. There has since been much speculation about gravity and antimatter. The theoretical consensus is that any laboratory mass must be attracted6 by the Earth, although some authors have considered the cosmological consequences if antimatter should be repelled by matter7-10. In the general theory of relativity, the weak equivalence principle (WEP) requires that all masses react identically to gravity, independent of their internal structure. Here we show that antihydrogen atoms, released from magnetic confinement in the ALPHA-g apparatus, behave in a way consistent with gravitational attraction to the Earth. Repulsive 'antigravity' is ruled out in this case. This experiment paves the way for precision studies of the magnitude of the gravitational acceleration between anti-atoms and the Earth to test the WEP.

4.
Rev Sci Instrum ; 93(12): 123303, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36586896

RESUMEN

We present a compact velocity-map imaging (VMI) spectrometer for photoelectron imaging at 100 MHz repetition rate. Ultrashort pulses from a near-infrared frequency comb laser are amplified in a polarization-insensitive passive femtosecond enhancement cavity. In the focus, multi-photon ionization (MPI) of gas-phase atoms is studied tomographically by rotating the laser polarization. We demonstrate the functioning of the VMI spectrometer by reconstructing photoelectron angular momentum distributions from xenon MPI. Our intra-cavity VMI setup collects electron energy spectra at high rates, with the advantage of transferring the coherence of the cavity-stabilized femtosecond pulses to the electrons. In addition, the setup will allow studies of strong-field effects in nanometric tips.

5.
Rev Sci Instrum ; 92(8): 083203, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-34470420

RESUMEN

We present a novel ultrastable superconducting radio-frequency (RF) ion trap realized as a combination of an RF cavity and a linear Paul trap. Its RF quadrupole mode at 34.52 MHz reaches a quality factor of Q ≈ 2.3 × 105 at a temperature of 4.1 K and is used to radially confine ions in an ultralow-noise pseudopotential. This concept is expected to strongly suppress motional heating rates and related frequency shifts that limit the ultimate accuracy achieved in advanced ion traps for frequency metrology. Running with its low-vibration cryogenic cooling system, electron-beam ion trap, and deceleration beamline supplying highly charged ions (HCIs), the superconducting trap offers ideal conditions for optical frequency metrology with ionic species. We report its proof-of-principle operation as a quadrupole-mass filter with HCIs and trapping of Doppler-cooled 9Be+ Coulomb crystals.

6.
Neth Heart J ; 29(7-8): 383-393, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34125353

RESUMEN

OBJECTIVE: Recent studies have reported suboptimal up-titration of heart failure (HF) therapies in patients with heart failure and a reduced ejection fraction (HFrEF). Here, we report on the achieved doses after nurse-led up-titration, reasons for not achieving the target dose, subsequent changes in left ventricular ejection fraction (LVEF), and mortality. METHODS: From 2012 to 2018, 378 HFrEF patients with a recent (< 3 months) diagnosis of HF were referred to a specialised HF-nurse led clinic for protocolised up-titration of guideline-directed medical therapy (GDMT). The achieved doses of GDMT at 9 months were recorded, as well as reasons for not achieving the optimal dose in all patients. Echocardiography was performed at baseline and after up-titration in 278 patients. RESULTS: Of 345 HFrEF patients with a follow-up visit after 9 months, 69% reached ≥ 50% of the recommended dose of renin-angiotensin-system (RAS) inhibitors, 73% reached ≥ 50% of the recommended dose of beta-blockers and 77% reached ≥ 50% of the recommended dose of mineralocorticoid receptor antagonists. The main reasons for not reaching the target dose were hypotension (RAS inhibitors and beta-blockers), bradycardia (beta-blockers) and renal dysfunction (RAS inhibitors). During a median follow-up of 9 months, mean LVEF increased from 27.6% at baseline to 38.8% at follow-up. Each 5% increase in LVEF was associated with an adjusted hazard ratio of 0.84 (0.75-0.94, p = 0.002) for mortality and 0.85 (0.78-0.94, p = 0.001) for the combined endpoint of mortality and/or HF hospitalisation after a mean follow-up of 3.3 years. CONCLUSIONS: This study shows that protocolised up-titration in a nurse-led HF clinic leads to high doses of GDMT and improvement of LVEF in patients with new-onset HFrEF.

7.
Opt Express ; 29(2): 2624-2636, 2021 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-33726454

RESUMEN

We have developed an extreme ultraviolet (XUV) frequency comb for performing ultra-high precision spectroscopy on the many XUV transitions found in highly charged ions (HCI). Femtosecond pulses from a 100 MHz phase-stabilized near-infrared frequency comb are amplified and then fed into a femtosecond enhancement cavity (fsEC) inside an ultra-high vacuum chamber. The low-dispersion fsEC coherently superposes several hundred incident pulses and, with a single cylindrical optical element, fully compensates astigmatism at the w0 = 15 µm waist cavity focus. With a gas jet installed there, intensities reaching ∼ 1014 W/cm2 generate coherent high harmonics with a comb spectrum at 100 MHz rate. We couple out of the fsEC harmonics from the 7th up to the 35th (42 eV; 30 nm) to be used in upcoming experiments on HCI frequency metrology.

8.
Neth Heart J ; 29(7-8): 402-408, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33594591

RESUMEN

BACKGROUND: Transcatheter atrial septal defect (ASD) and patent foramen ovale (PFO) closure might have opposite short- and long-term haemodynamic consequences compared with restricted interatrial shunt creation, which recently emerged as a potential treatment modality for patients with heart failure with preserved ejection fraction (HFpEF). Given the opposing approaches of ASD and PFO closure versus shunt creation, we investigated the early and sustained cardiac structural and functional changes following transcatheter ASD or PFO closure. METHODS: In this retrospective study, adult secundum-type ASD and PFO patients with complete echocardiography examinations at baseline and at 1­day and 1­year follow-up who also underwent transcatheter closure between 2013 and 2017 at the University Medical Centre Groningen, the Netherlands were included. RESULTS: Thirty-nine patients (mean age 48 ± standard deviation 16 years, 61.5% women) were included. Transcatheter ASD/PFO closure resulted in an early and persistent decrease in right ventricular systolic and diastolic function. Additionally, transcatheter ASD/PFO closure resulted in an early and sustained favourable response of left ventricular (LV) systolic function, but also in deterioration of LV diastolic function with an increase in LV filling pressure (LVFP), as assessed by echocardiography. Age (ß = 0.31, p = 0.009) and atrial fibrillation (AF; ß = 0.24, p = 0.03) were associated with a sustained increase in LVFP after transcatheter ASD/PFO closure estimated by mean E/e' ratio (i.e. ratio of mitral peak velocity of early filling to diastolic mitral annular velocity). In subgroup analysis, this was similar for ASD and PFO closure. CONCLUSION: Older patients and patients with AF were predisposed to sustained increases in left-sided filling pressures resembling HFpEF following ASD or PFO closure. Consequently, these findings support the current concept that creating a restricted interatrial shunt might be beneficial, particularly in elderly HFpEF patients with AF.

9.
Opt Lett ; 45(8): 2156-2159, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-32287180

RESUMEN

We raise the power from a commercial 10 W frequency comb inside an enhancement cavity and perform multi-photon ionization of gas-phase atoms at 100 MHz for the first time, to the best of our knowledge. An intra-cavity velocity-map-imaging setup collects electron-energy spectra of xenon at rates several orders of magnitude higher than those of conventional laser systems. Consequently, we can use much lower intensities ${\sim}{{10}^{12}} \;{\rm W}/{{\rm cm}^2} $∼1012W/cm2 without increasing acquisition times above just a few seconds. The high rate and coherence of the stabilized femtosecond pulses are known to be transferred to the actively stabilized cavity and will allow studying purely perturbative multi-photon effects, paving the road towards a new field of precision tests in nonlinear physics.

10.
Artículo en Ruso | MEDLINE | ID: mdl-33459540

RESUMEN

OBJECTIVE: To evaluate the efficacy and safety of modified-release (MR) betahistine (48 mg once daily) versus betaserc (24 mg twice daily) in patients with Meniere's disease or vestibular vertigo. MATERIAL AND METHODS: A multicentre, double-blind, randomized clinical study in patients with an established diagnosis of Meniere's disease (35%) or vestibular vertigo (65%) was carried out. A total of 264 patients were randomized (132 in each group).The inclusion criteria were a Dizziness Handicap Inventory (DHI) total score of more than 30 points and at least 2 vertigo attacks within the previous 4 weeks. The primary efficacy variable was the change in the DHI total score from baseline to after 12 weeks of treatment. The predefined non-inferiority margin was set at 9 points for the DHI total score. RESULTS: After 12 weeks of treatment, the DHI total score was significantly (p<0.001) decreased compared with baseline, by 32.0±20.7 in the betahistine MR group and by 31.8±19.8 in the betaserc group. The adjusted difference in the change in the DHI total score with a one-sided 97.5% CI was 0.9 (--; 5.3) points, the upper confidence limit (+5.3) fell below the predefined margin of non-inferiority of 9 points, and the non-inferiority of betahistine MR to betaserc was established. The treatment groups were comparable in terms of reduced scores for the functional, emotional and physical subdomains of DHI; reduced frequency, intensity and duration of vertigo attacks; decreased proportion of patients with prolonged attacks and severe symptoms during attacks; and scores on the Clinical Global Impression - Improvement scale. The safety profile of betahistine MR was comparable to that of betaserc, the most frequently reported adverse event was headache in both treatment groups. CONCLUSION: Betahistine MR (48 mg once daily) is non-inferior to betaserc (24 mg twice daily) in patients with Meniere's disease or vestibular vertigo and has a comparable safety profile.


Asunto(s)
Betahistina , Enfermedad de Meniere , Betahistina/efectos adversos , Método Doble Ciego , Emociones , Humanos , Enfermedad de Meniere/complicaciones , Enfermedad de Meniere/tratamiento farmacológico , Vértigo/tratamiento farmacológico
11.
Scand J Med Sci Sports ; 28(6): 1708-1714, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29377400

RESUMEN

This study describes the prevalence, incidence density, severity, and nature of injuries in elite field hockey players over the Dutch 2015-2016 season. Eighty players answered a baseline questionnaire and were subsequently followed up every 2 weeks to report the hours spent on training/competition and experienced injuries, which were registered using the Oslo Sports Trauma Research Centre Questionnaire on Health Problems. Of the 74 players included in the analysis, 52 (70%) reported 112 injuries. Eighty-seven injuries (78%) received medical attention, and 56 (50%) led to training/competition time-loss. Thirty-four injuries (30%) hampered players' availability to train and compete. Most of the injuries (74%) were not caused by any contact. The mean prevalence of injury was 29% (95% confidence interval [CI] 3-55) for all, 9% (95% CI 0-20) for acute, and 14% (95% CI 0-36) for overuse injuries. Players sustained 3.5 (95% CI 2.5-4.5) new acute injuries per 1000 hours of training and 12.3 (95% CI 7.6-17.0) per 1000 hours of competition. The median of the severity score was 28 from 100 (25%-75% interquartile range [IQR] 16-42) for all, 35 (IQR 23-53) for acute, and 21 (IQR 16-31) for overuse injuries. On average, 1 in 4 elite field hockey players experiences an injury within a 2-week period during the season. Although acute injuries are common, overuse injuries pose a comparable problem in elite field hockey. As injuries are a burden on players' health and may hamper performance and availability to train and compete, prevention is of great importance.


Asunto(s)
Traumatismos en Atletas/epidemiología , Trastornos de Traumas Acumulados/epidemiología , Hockey/lesiones , Adolescente , Adulto , Atletas , Femenino , Humanos , Masculino , Países Bajos , Prevalencia , Estudios Prospectivos , Encuestas y Cuestionarios , Adulto Joven
12.
Scand J Med Sci Sports ; 27(1): 93-98, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26648482

RESUMEN

Although injuries to the upper extremity are most costly, the picture of the upper extremity injury problem remains incomplete. This study is the first to describe the etiology and mechanisms of upper extremity injuries in Danish children. A 2.5-year observational prospective cohort study was conducted to record upper extremity injuries in 1048 children. Data were weekly collected by sending a text message. A total of 176 upper extremity injuries were reported (128 acute injuries). Of the acute upper extremity injuries, 55% were sprains, 47% occurred in the hand/wrist, and 53% of cases were caused by a fall. When corrected for exposure to physical activity, this resulted in an acute upper extremity injury incidence density of 0.18 per 1000 h of physical activity. The odds of sustaining an upper extremity injury was higher in the older children (HR: 1.84, 95% CI: 1.10-3.09), a tendency was found suggesting that girls are at increased acute upper extremity risk compared to boys (HR: 1.40 95% CI: 0.97-2.04). The findings that most injuries occur after a fall, that injury risk increases over age and that girls seem to be at increased injury risk provides essential information to guide future childhood injury prevention.


Asunto(s)
Accidentes por Caídas/estadística & datos numéricos , Trastornos de Traumas Acumulados/epidemiología , Fracturas Óseas/epidemiología , Traumatismos de la Mano/epidemiología , Lesiones del Hombro/epidemiología , Esguinces y Distensiones/epidemiología , Traumatismos de la Muñeca/epidemiología , Factores de Edad , Traumatismos del Brazo/epidemiología , Niño , Estudios de Cohortes , Dinamarca/epidemiología , Ejercicio Físico , Femenino , Humanos , Incidencia , Masculino , Análisis Multivariante , Oportunidad Relativa , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Factores de Riesgo , Factores Sexuales
13.
J Chem Phys ; 144(24): 244201, 2016 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-27369508

RESUMEN

A novel mid-infrared/near-infrared double resonant absorption setup for studying infrared-inactive vibrational states is presented. A strong vibrational transition in the mid-infrared region is excited using an idler beam from a singly resonant continuous-wave optical parametric oscillator, to populate an intermediate vibrational state. High output power of the optical parametric oscillator and the strength of the mid-infrared transition result in efficient population transfer to the intermediate state, which allows measuring secondary transitions from this state with a high signal-to-noise ratio. A secondary, near-infrared transition from the intermediate state is probed using cavity ring-down spectroscopy, which provides high sensitivity in this wavelength region. Due to the narrow linewidths of the excitation sources, the rovibrational lines of the secondary transition are measured with sub-Doppler resolution. The setup is used to access a previously unreported symmetric vibrational state of acetylene, ν1+ν2+ν3+ν4 (1)+ν5 (-1) in the normal mode notation. Single-photon transitions to this state from the vibrational ground state are forbidden. Ten lines of the newly measured state are observed and fitted with the linear least-squares method to extract the band parameters. The vibrational term value was measured to be at 9775.0018(45) cm(-1), the rotational parameter B was 1.162 222(37) cm(-1), and the quartic centrifugal distortion parameter D was 3.998(62) × 10(-6) cm(-1), where the numbers in the parenthesis are one-standard errors in the least significant digits.

14.
Obes Rev ; 16(10): 831-42, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26098701

RESUMEN

Hypertension is increasingly common in overweight and obese children. The mechanisms behind the development of hypertension in obesity are complex, and evidence is limited. In order to effectively treat obese children for hypertension, it is important to have a deeper understanding of the pathophysiology of hypertension in obese children. The present review summarizes the main factors associated with hypertension in obese children and discusses their potential role in its pathophysiology. Systematic searches were conducted in PubMed and EMBASE for articles published up to October 2014. In total, 60 relevant studies were included. The methodological quality of the included studies ranged from weak to strong. Several factors important in the development of hypertension in obese children have been suggested, including endocrine determinants, such as corticosteroids and adipokines, sympathetic nervous system activity, disturbed sodium homeostasis, as well as oxidative stress, inflammation and endothelial dysfunction. Understanding the pathophysiology of hypertension in overweight and obese children is important and could have implications for its screening and treatment. Based on solely cross-sectional observational studies, it is impossible to infer causality. Longitudinal studies of high methodological quality are needed to gain more insight into the complex mechanisms behind the development of hypertension in obese children.


Asunto(s)
Adipoquinas/metabolismo , Hipertensión/fisiopatología , Obesidad Infantil/fisiopatología , Índice de Masa Corporal , Niño , Humanos , Hipertensión/etiología , Hipertensión/prevención & control , Resistencia a la Insulina , Estrés Oxidativo , Obesidad Infantil/complicaciones , Obesidad Infantil/prevención & control , Factores de Riesgo
15.
Biomed Chromatogr ; 26(7): 789-96, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22020542

RESUMEN

Prednisolone (PLN) and prednisone (PN) are widely used glucocorticoids. Drug monitoring of PLN and PN is not routinely done owing to the need for multiple blood sampling and challenging measurement of unbound PLN and PN in blood. Here we present a robust method for quantification of cortisol, PLN and PN in serum, ultrafiltrate and saliva by on-line solid-phase extraction LC-MS/MS. The method is linear for the three analytes over the range of 6-1400 nmol/L for serum and 2-450 nmol/L for ultrafiltrate and saliva. Within-run precision of all three analytes was <10% and total precision was <15%. This method was applied to create time-concentration profiles of cortisol, PLN and PN after an oral dose of prednisolone in a healthy volunteer. Salivary levels of PLN correlated well with ultrafiltrate levels (p < 0.01), while this correlation was only marginal for PN (p = 0.052). The PN/PLN ratio was significantly higher in saliva than in ultrafiltrate and serum (p < 0.01). Addition sums of both metabolites in saliva showed excellent correlation with those of ultrafiltrate (p < 0.01). These findings have not been presented before and may have important implications for future studies concerning drug monitoring of PLN and PN in saliva.


Asunto(s)
Cromatografía Liquida/métodos , Hidrocortisona/sangre , Prednisolona/sangre , Prednisona/sangre , Saliva/química , Extracción en Fase Sólida/métodos , Monitoreo de Drogas , Humanos , Hidrocortisona/química , Hidrocortisona/farmacocinética , Modelos Lineales , Prednisolona/química , Prednisolona/farmacocinética , Prednisona/química , Prednisona/farmacocinética , Reproducibilidad de los Resultados , Espectrometría de Masas en Tándem/métodos , Transcortina/análisis , Ultrafiltración/métodos
16.
Vaccine ; 29(34): 5785-92, 2011 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-21624411

RESUMEN

Several inactivated influenza vaccine formulations for systemic administration in man are currently available for annual (seasonal) immunization: split virus and subunit (either plain-aqueous, or virosomal, or adjuvanted by MF59). From a literature search covering the period 1978-2009, 33 articles could be identified, which described randomized clinical trials comparing at least two of the four vaccine formulations with respect to serum hemagglutination inhibition (HI) antibody response, local and systemic vaccine reactions and serious adverse events after vaccination, and employing seasonal vaccine components and doses. In total, 9121 vaccinees of all ages, either healthy or with underlying diseases, were involved. Most vaccinees were primed or had been vaccinated in previous years. For immunogenicity, homologous post-vaccination geometric mean HI titers (GMTs) were analyzed by a random effects model for continuous data. Unreported standard deviations (SD) were addressed by imputing assumed SD-values. Age and health state of the vaccinees appeared to have little influence on the outcome. The immunogenicity of split, aqueous and virosomal subunit formulations were similar, with geometric mean ratio values (GMR, quotient of paired GMT-values) varying around one (0.93-1.24). The MF59-adjuvanted subunit vaccine induced, on average, larger antibody titers than the non-adjuvanted vaccine formulations, but the absolute increase was small (GMR-values varying between 1.25 and 1.40). Vaccine reactions were analyzed using a random effects model for binary data. Local and systemic reactogenicity was similar among non-adjuvanted formulations. The adjuvanted subunit formulation was more frequently associated with local reactions than the non-adjuvanted formulations (rate ratio: 2.12, significant). Systemic reactions were similar among all vaccine formulations. The original articles emphasized the mild and transient character of the vaccine reactions and the absence of serious vaccine-related adverse events. This adequate amount of evidence led to the conclusion that all the currently available inactivated influenza vaccine formulations are safe, well tolerated and similarly effective to control seasonal influenza outbreaks across primed populations and age ranges.


Asunto(s)
Anticuerpos Antivirales/sangre , Vacunas contra la Influenza , Vacunas de Productos Inactivados , Adyuvantes Inmunológicos/administración & dosificación , Adyuvantes Inmunológicos/efectos adversos , Ensayos Clínicos como Asunto , Pruebas de Inhibición de Hemaglutinación , Humanos , Subtipo H1N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza/administración & dosificación , Vacunas contra la Influenza/efectos adversos , Vacunas contra la Influenza/inmunología , Gripe Humana/inmunología , Gripe Humana/prevención & control , Vacunas de Productos Inactivados/administración & dosificación , Vacunas de Productos Inactivados/efectos adversos , Vacunas de Productos Inactivados/inmunología
17.
Vaccine ; 27(18): 2414-7, 2009 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-19368782

RESUMEN

Between 1982 and 2006, 76 clinical studies (including the annual update studies required for licensing in Europe) were performed with the trivalent inactivated subunit influenza vaccine Influvac. In all, 6415 subjects were vaccinated, of whom 5034 were eligible for safety evaluation and 4534 for efficacy evaluation. Treatment-emergent adverse events occurred in 13.7% of subjects. Transient mild-to-moderate local and systemic reactions occurred in up to half of subjects. Post-marketing surveillance confirmed the well-established safety profile reported for inactivated influenza vaccines. All three serological criteria for immunogenicity of the Committee for Medicinal Products for Human Use (CHMP) were met for all three virus strain (sub)types in healthy adults, elderly (over 60 years), nursing home residents, and those at high risk of influenza-related complications. In an additional trial in children aged 3 -- 12 years, all three CHMP criteria for adults were met for all three virus strains. Influvac is thus immunogenic and safe, and is a suitable vaccine to combat the annually recurring medical and economic burden of influenza epidemics.


Asunto(s)
Vacunas contra la Influenza/efectos adversos , Vacunas contra la Influenza/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antivirales/sangre , Humanos , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto , Vacunas de Productos Inactivados/efectos adversos , Vacunas de Productos Inactivados/inmunología , Vacunas de Subunidad/efectos adversos , Vacunas de Subunidad/inmunología
18.
Kidney Int ; 72(3): 265-8, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17495859

RESUMEN

A low nephron number has been advocated to explain the association between intrauterine growth restriction (IUGR) and hypertension in later life. IUGR not only leads to a low birth weight but is also hypothesized to reprogram nephrogenesis, which results in a low nephron endowment. Several methods are used to estimate the total glomerular number, but only stereological techniques result in accurate (unbiased) and precise (reproducible) data. Several studies, both in humans and animal models that have used these methods indeed revealed that IUGR leads to a low nephron number. According to the hyperfiltration hypothesis, this reduction in renal mass is supposed to lead to glomerular hyperfiltration and hypertension in remnant nephrons with subsequent glomerular injury with proteinuria, systemic hypertension and glomerulosclerosis. Even though IUGR is associated with both a low nephron endowment and an increased risk of hypertension, only circumstantial evidence is available to support the hyperfiltration hypothesis after prenatal programming. A prerequisite for establishment of this association in long-term, prospective follow-up studies is the ability to estimate glomerular numbers in living human beings, for which a further advancement in radiological techniques is necessary. Only then can the association between nephron endowment and blood pressure in humans be studied more conclusively.


Asunto(s)
Presión Sanguínea/fisiología , Nefronas/embriología , Nefronas/fisiología , Retardo del Crecimiento Fetal/fisiopatología , Tasa de Filtración Glomerular/fisiología , Humanos , Hipertensión/etiología , Hipertensión/fisiopatología , Nefronas/anatomía & histología
19.
Vaccine ; 24(44-46): 6629-31, 2006 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-16901593

RESUMEN

Several approaches are currently being pursued in order to improve the efficacy of influenza vaccines in elderly individuals and others who have impaired immune responses to conventional influenza vaccines. There are two influenza vaccines available for elderly subjects: Fluad (Chiron) and Invivac (Solvay Pharmaceuticals). The present clinical study was a randomized, endpoint-blind, parallel group study in elderly subjects aged 61 years and older to investigate the safety and immunogenicity of these vaccines as compared to a standard influenza vaccine Invivac (Solvay Pharmaceuticals). The three vaccines had similar immunogenicity results, whereas the tolerability profile of Invivac was better as compared to Fluad.


Asunto(s)
Adyuvantes Inmunológicos/farmacología , Sistemas de Liberación de Medicamentos , Vacunas contra la Influenza/administración & dosificación , Vacunas de Productos Inactivados/administración & dosificación , Vacunas de Virosoma/administración & dosificación , Adyuvantes Inmunológicos/efectos adversos , Anciano , Anciano de 80 o más Años , Humanos , Vacunas contra la Influenza/efectos adversos , Vacunas contra la Influenza/inmunología , Vacunas contra la Influenza/normas , Seguridad , Vacunas de Productos Inactivados/efectos adversos , Vacunas de Productos Inactivados/inmunología , Vacunas de Subunidad/efectos adversos , Vacunas de Subunidad/inmunología , Vacunas de Virosoma/efectos adversos , Vacunas de Virosoma/inmunología
20.
J Biopharm Stat ; 16(4): 443-52, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16892906

RESUMEN

This paper presents an integrated statistical approach to the analysis of influenza vaccine lot consistency studies in which three lots are compared. The approach ensures that the overall Type I error rate (i.e., the probability of wrongly concluding that the lots are similar) is controlled. It is argued that the optimum efficacy measure is the geometric mean titer. The approach is demonstrated using data from a randomized, double-blind lot consistency study in which three consecutive production lots of Solvay Pharmaceuticals' new, virosomal subunit influenza vaccine Invivac were compared.


Asunto(s)
Industria Farmacéutica/estadística & datos numéricos , Industria Farmacéutica/normas , Vacunas contra la Influenza/normas , Método Doble Ciego , Pruebas de Inhibición de Hemaglutinación/normas , Pruebas de Inhibición de Hemaglutinación/estadística & datos numéricos , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos
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