2,086 research outputs found
Sex hormones in allergic conjunctivitis: altered levels of circulating androgens and estrogens in children and adolescents with vernal keratoconjunctivitis
PURPOSE:
Vernal keratoconjunctivitis (VKC) is a chronic allergic disease mainly affecting boys in prepubertal age and usually recovering after puberty. To evaluate a possible role of sex hormones in VKC, serum levels of sex hormones in children and adolescents with VKC were assessed.
METHODS:
12 prepubertal and 7 early pubertal boys with active VKC and 6 male patients with VKC in remission phase at late pubertal age and 48 healthy age and sex-matched subjects were included. Serum concentration of estrone, 17 beta-estradiol, dehydroepiandrosterone-sulfate, total testosterone and free testosterone, dihydrotestosterone (DHT), cortisol, delta-4-androstenedione, follicle-stimulating hormone, luteinizing hormone, and sex-hormones binding globuline (SHBG) were evaluated.
RESULTS:
Serum levels of Estrone were significantly increased in all groups of patients with VKC when compared to healthy controls (P < 0.001). Prepubertal and early pubertal VKC showed a significant decrease in DHT (P = 0.007 and P = 0.028, resp.) and SHBG (P = 0.01 and P = 0.002, resp.) when compared to controls and serum levels of SHBG were increased in late pubertal VKC in remission phase (P = 0.007).
CONCLUSIONS AND RELEVANCE:
VKC patients have different circulating sex hormone levels in different phases of the disease and when compared to nonallergic subjects. These findings suggest a role played by sex hormones in the pathogenesis and/or activity of VKC
Progress towards Bell-type polarization experiment with thermal neutrons
Experimental tests of Bell-type inequalities distinguishing between quantum
mechanics and local realistic theories remain of considerable interest if
performed on massive particles, for which no conclusive result has yet been
obtained. Only two-particle experiments may specifically test the concept of
spatial nonlocality in quantum theory, whereas single-particle experiments may
generally test the concept of quantum noncontextuality. Here we have performed
the first Bell-type experiment with a beam of thermal-neutron pairs in the
singlet state of spin, as originally suggested by J. S. Bell. These
measurements confirm the quantum-theoretical predictions, in agreement with the
results of the well-known polarization experiments carried out on optical
photons years ago
Optical properties of the charge-density-wave polychalcogenide compounds Te (=Nd, Sm and Gd)
We investigate the rare-earth polychalcogenide Te (=Nd, Sm and
Gd) charge-density-wave (CDW) compounds by optical methods. From the absorption
spectrum we extract the excitation energy of the CDW gap and estimate the
fraction of the Fermi surface which is gapped by the formation of the CDW
condensate. In analogy to previous findings on the related Te (n=2 and
3) families, we establish the progressive closing of the CDW gap and the
moderate enhancement of the metallic component upon chemically compressing the
lattice
Ergodicity breaking in strong and network-forming glassy system
The temperature dependence of the non-ergodicity factor of vitreous GeO,
, as deduced from elastic and quasi-elastic neutron scattering
experiments, is analyzed. The data are collected in a wide range of
temperatures from the glassy phase, up to the glass transition temperature, and
well above into the undercooled liquid state. Notwithstanding the investigated
system is classified as prototype of strong glass, it is found that the
temperature- and the -behavior of follow some of the predictions
of Mode Coupling Theory. The experimental data support the hypothesis of the
existence of an ergodic to non-ergodic transition occurring also in network
forming glassy systems
Effect of recombinant human nerve growth factor eye drops in patients with dry eye: a phase IIa, open label, multiple-dose study
Background: Dry eye disease (DED) affects more than 14% of the elderly population causing decrease of quality of life, high costs and vision impairment. Current treatments for DED aim at lubricating and controlling inflammation of the ocular surface. Development of novel therapies targeting different pathogenic mechanisms is sought-after. The aim of this study is to evaluate safety and efficacy of recombinant human nerve growth factor (rhNGF) eye drops in patients with DED. Methods: Forty consecutive patients with moderate to severe DED were included in a phase IIa, prospective, open label, multiple-dose, clinical trial to receive rhNGF eye drops at 20 μg/mL (Group 1: G1) or at 4 μg/mL (Group 2: G2) concentrations, two times a day in both eyes for 28 days (NCT02101281). The primary outcomes measures were treatment-emerged adverse events (AE), Symptoms Assessment in Dry Eye (SANDE) scale, ocular surface staining and Schirmer test. Results: Of 40 included patients, 39 completed the trial. Both tested rhNGF eye drop concentrations were safe and well tolerated. Twenty-nine patients experienced at least one AE (14 in G1 and 15 in G2), of which 11 had at least 1 related AE (8 in G1 and 3 in G2). Both frequency and severity of DED symptoms and ocular surface damage showed significant improvement in both groups, while tear function improved only in G1. Conclusions: The data of this study indicate that rhNGF eye drops in both doses is safe and effective in improving symptoms and signs of DED. Randomised clinical trials are ongoing to confirm the therapeutic benefit of rhNGF in DED. Trial registration number: NCT02101281
Rare diseases of the anterior segment of the eye: update on diagnosis and management
This special issue is focused on the current approaches used to identify and manage rare diseases of the anterior segment
of the eye, which range from congenital to acquired disorders that are caused by ocular or systemic conditions and often
have consequences that extend beyond the anterior segment of the eye
Further evidence of antibunching of two coherent beams of fermions
We describe an experiment confirming the evidence of the antibunching effect
on a beam of non interacting thermal neutrons. The comparison between the
results recorded with a high energy-resolution source of neutrons and those
recorded with a broad energy-resolution source enables us to clarify the role
played by the beam coherence in the occurrence of the antibunching effect.Comment: 4 pages, 3 figure
A system model of the effects of exercise on plasma Interleukin-6 dynamics in healthy individuals: Role of skeletal muscle and adipose tissue
Interleukin-6 (IL-6) has been recently shown to play a central role in glucose homeostasis,
since it stimulates the production and secretion of Glucagon-like Peptide-1 (GLP-1) from
intestinal L-cells and pancreas, leading to an enhanced insulin response. In resting conditions,
IL-6 is mainly produced by the adipose tissue whereas, during exercise, skeletal muscle
contractions stimulate a marked IL-6 secretion as well. Available mathematical models
describing the effects of exercise on glucose homeostasis, however, do not account for this
IL-6 contribution. This study aimed at developing and validating a system model of exercise’s
effects on plasma IL-6 dynamics in healthy humans, combining the contributions of
both adipose tissue and skeletal muscle. A two-compartment description was adopted to
model plasma IL-6 changes in response to oxygen uptake’s variation during an exercise
bout. The free parameters of the model were estimated by means of a cross-validation procedure
performed on four different datasets. A low coefficient of variation (<10%) was found
for each parameter and the physiologically meaningful parameters were all consistent with
literature data. Moreover, plasma IL-6 dynamics during exercise and post-exercise were
consistent with literature data from exercise protocols differing in intensity, duration and
modality. The model successfully emulated the physiological effects of exercise on plasma
IL-6 levels and provided a reliable description of the role of skeletal muscle and adipose tissue
on the dynamics of plasma IL-6. The system model here proposed is suitable to simulate
IL-6 response to different exercise modalities. Its future integration with existing models
of GLP-1-induced insulin secretion might provide a more reliable description of exercise’s
effects on glucose homeostasis and hence support the definition of more tailored interventions
for the treatment of type 2 diabetes
Disentangling time-focusing from beam divergence: a novel approach for high-flux thermal neutron spectroscopy at continuous and long-pulse sources
We present the concept of a novel time-focusing technique for neutron
spectrometers, which allows to disentangle time-focusing from beam divergence.
The core of this approach is a double rotating-crystal monochromator that can
be used to extract a larger wavelength band from a white beam, thus providing a
higher flux at the sample compared to standard time-of-flight instruments, yet
preserving energy resolution and beam collimation. The performances of a
spectrometer based on this approach are quantitatively discussed in terms of
possible incident wavelengths, flux at the sample and -resolution.
Analytical estimates suggest flux gains of about one order of magnitude at
comparable resolutions in comparison to conventional time-of-flight
spectrometers. Moreover, the double monochromator configuration natively shifts
the sample away from the source line-of-sight, thus significantly improving the
signal-to-noise ratio. The latter, in combination with a system that does not
increase the beam divergence, brings the further advantage of a cleaner access
to the low- region, which is recognized to be of fundamental interest for
magnetism and for disordered materials, from glasses to biological systems
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