Follicle development is the result of a balanced ratio between cell proliferation and cell death. Previous studies demonstrated
differential mitotic responses to insulin-like growth factor (IGF)-I ...and epidermal growth factor (EGF) of cumulus cells (CC)
and mural granulosa cells (MGC). Because cell-to-cell contact seems to modulate the occurrence of programmed cell death, the
present experiments investigated the role of cell association in mediating apoptosis and the mitogenic responses to these
growth factors of CC and MGC. Cumulus cells were cultured either as intact cumulus-oocyte complexes (COC) or after dissociation
with EGTA + sucrose, in the presence of 50 ng/ml IGF-I, 5 ng/ml EGF, or both. Mural granulosa cells from the same follicles
were similarly cultured either as cell aggregates or as dissociated cells. Synthesis of DNA was assessed by measurement of
3 Hthymidine incorporation during the last 6 h of a 24-h culture in TCM199. Percentages of cells undergoing apoptosis were
determined immunohistochemically in intact COC and GC aggregates, before and after dissociation as well as after the culture
period. Epidermal growth factor and IGF-I stimulated DNA synthesis in both cell types; however, EGF inhibited the action of
IGF-I in intact COC but not in MGC. Compared to nondissociated cells, dissociation resulted in a reduction of the mitogenic
response of CC to both growth factors and of MGC to EGF. Unlike the response of intact COC to combined treatment with the
two growth factors, dissociated CC displayed additive responses to the two growth factors in combination. Addition of denuded
oocytes to cultures of dissociated CC enhanced both basal and growth factor-stimulated DNA synthesis but did not restore the
inhibitory effect of EGF on the IGF-I response characteristic of intact COC. A significant proportion of intact MGC aggregates
underwent apoptosis after 24 h of culture, while no increase of apoptotic cells was observed in intact COC. A dramatic increase
in the percentage of apoptotic cells was observed in both CC and MGC when cell-cell contact was interrupted, and EGF and IGF-I
were able to partially prevent its occurrence. Taken together these data showed that CC and MGC exhibit qualitatively and
quantitatively different responses to IGF-I when cultured in the presence of EGF both in terms of DNA synthesis and onset
of apoptosis. Moreover, the disruption of cell-cell contact was a major factor reducing cell proliferation and inducing apoptosis
among both subsets of GC.
In recent onset of type 1 diabetes, the residual beta cell function, assessed by baseline and/or stimulated C-peptide secretion, can be a useful parameter to establish the extension of beta cell ...destruction. How metabolic parameters at diagnosis influence residual C-peptide secretion is not well established.
We analyzed 553 consecutive patients with recent onset (<4 weeks) of type 1 diabetes (250 females and 303 males, mean age 15+/-8 years). Baseline and stimulated C-peptide by i.v. glucagon were evaluated using a highly sensitive radio-immunoassay. Metabolic parameters including blood glucose, HbA1c, insulin dose, and BMI were also evaluated.
Baseline and stimulated C-peptide were 0.26+/-0.22 and 0.47+/-0.38 nmol/l and correlated positively with age (p<0.001). There was no significant correlation between C-peptide and blood glucose at diagnosis. BMI was positively correlated with both baseline and stimulated C-peptide secretion (p<0.001). By contrast, HbA1c levels inversely correlated with both baseline and stimulated C-peptide secretion (p<0.001).
In type 1 diabetes at diagnosis, baseline and stimulated C-peptide are higher in pubertal and young adult patients compared with pre-pubertal patients suggesting that such parameter can be used as an end point marker for studies aimed at protecting and/or restoring beta cells in patients with substantial beta cell function. High levels of HbA1c and lower BMI are dependent variables of C-peptide values.
Direct Dark Matter searches are nowadays one of the most fervid research topics with many experimental efforts devoted to the search for nuclear recoils induced by the scattering of Weakly ...Interactive Massive Particles (WIMPs). Detectors able to reconstruct the direction of the nucleus recoiling against the scattering WIMP are opening a new frontier to possibly extend Dark Matter searches beyond the neutrino background. Exploiting directionality would also prove the galactic origin of Dark Matter with an unambiguous signal-to-background separation. Indeed, the angular distribution of recoiled nuclei is centered around the direction of the Cygnus constellation, while the background distribution is expected to be isotropic. Current directional experiments are based on gas TPC whose sensitivity is limited by the small achievable detector mass. In this paper we present the discovery potential of a directional experiment based on the use of a solid target made of newly developed nuclear emulsions and of optical read-out systems reaching unprecedented nanometric resolution.
Thermal poling has been investigated in silica-based glasses prepared by the sol–gel method. Samples with different OH-content (from 40
ppm to few 10
3
ppm), doping (oxygen-vacancies, substitutional ...Sn, SnO
2 clusters) and post-synthesis treatment (X-ray irradiation) have been heated in vacuum at 280
°C with an applied voltage of 4
kV. Second-order non-linearity has been observed after poling, with
χ
(2) of the order of 0.1
pm/V. The comparison among samples suggests that OH-content is not the only factor responsible for the observed non-linearity.
The implementation of a database of digitised mammograms is discussed. The digitised images were collected beginning in 1999 by a community of physicists in collaboration with radiologists in several ...Italian hospitals as a first step in developing and implementing a computer-aided detection (CAD) system. All 3,369 mammograms were collected from 967 patients and classified according to lesion type and morphology, breast tissue and pathology type. A dedicated graphical user interface was developed to visualise and process mammograms to support the medical diagnosis directly on a high-resolution screen. The database has been the starting point for developing other medical imaging applications, such as a breast CAD, currently being upgraded and optimised for use in a distributed environment with grid services, in the framework of the Instituto Nazionale di Fisicia Nucleare (INFN)-funded Medical Applications on a Grid Infrastructure Connection (MAGIC)-5 project.
In the present work the effects produced by Eu3+ incorporation into sol-gel silica (doping level range: 0.001-10 mol%) are monitored by means of Fourier transform vibrational spectroscopy in the wave ...number range 200-3000 cm−1. Complementary microreflectance, TEM, and Raman spectroscopy measurements are also performed. By increasing the Eu3+ concentration up to 3 mol%, the intrinsic absorption/reflectance bands related to vibrational modes of O–Si–O groups are gradually modified for what concerns the peak position and intensity, and absorption shoulders attributable to the Eu3+ doping appear. At 10 mol% sharp, new, Eu-related peaks grow at the expenses of the intrinsic absorptions. The results can be explained in terms of Eu-rich cluster formation, as also supported by Raman spectra analysis and TEM images. The cluster sizes increase by increasing the Eu3+ concentration. Their structure, in which tetrahedral (SiO4)4- groups are still present, remains amorphous for Eu3+ concentration up to 3 mol%, turning into a nearly ordered arrangement for the higher one. The spectral analysis in the regions of the weaker absorptions due to combination and overtone modes further supports the results and allows to associate the fundamental and overtone frequencies for two modes in Eu3+ 10 mol% doped silica. In the framework of the Morse anharmonic oscillator model, the related anharmonicity parameters and binding energies were calculated and found close to those reported for (SiO4)4- groups.
Weather and the susceptibility of children to severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection is still a debated question and currently a hot topic, particularly in view of ...important decisions regarding opening schools. Therefore, we performed this prospective analysis of anti‐SARS‐CoV‐2 immunoglobulin G (IgG) antibodies in children with known household exposure to SARS‐CoV‐2 and compared their IgG status with the other adults exposed to the index case in the same household. A total of 30 families with a documented COVID‐19 index case were included. A total of 44 out of 80 household contacts (55%) of index patients had anti SARS‐CoV‐2 IgG antibodies. In particular, 16/27 (59,3%) adult partners had IgG antibodies compared with 28/53 (52,3%) of pediatric contacts (p > .05). Among the pediatric population, children ≥5 years of age had a similar probability of having SARS‐CoV‐2 IgG antibodies (21/39, 53.8%) compared to those less than 5 years old (7/14, 50%) (p > .05). Adult partners and children also had a similar probability of having SARS‐CoV‐2 IgG antibodies. Interestingly, 10/28 (35.7%) of children and 5/27 (18.5%) of adults with SARS‐CoV‐2 IgG antibodies were previously diagnosed as COVID‐19 cases. Our study shows evidence of a high rate of IgG antibodies in children exposed to SARS‐CoV‐2. This report has public health implications, highlighting the need to establish appropriate guidelines for school openings and other social activities related to childhood.
OBJECTIVE: We investigated whether supplementation of the active form of vitamin D (calcitriol) in recent-onset type 1 diabetes can protect β-cell function evaluated by C-peptide and improve glycemic ...control assessed by A1C and insulin requirement. RESEARCH DESIGN AND METHODS: Thirty-four subjects (aged 11-35 years, median 18 years) with recent-onset type 1 diabetes and high basal C-peptide >0.25 nmol/l were randomized in a double-blind trial to 0.25 μg/day calcitriol or placebo and followed-up for 2 years. RESULTS: At 6, 12, and 24 months follow-up, A1C and insulin requirement in the calcitriol group did not differ from the placebo group. C-peptide dropped significantly (P < 0.001) but similarly in both groups, with no significant differences at each time point. CONCLUSIONS: At the doses used, calcitriol is ineffective in protecting β-cell function in subjects (including children) with recent-onset type 1 diabetes and high C-peptide at diagnosis.
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