The aim of this study was to evaluate the presence of early vascular damage in young normal-weight women with polycystic ovary syndrome (PCOS). Thirty young normal-weight women with PCOS, who had no additional metabolic or cardiovascular diseases, and 30 healthy women (controls) matched for age and body mass index were studied. A complete hormonal assay was performed in each subject. Serum insulin and glucose levels were measured at baseline and after the oral glucose tolerance test. Plasma endothelin-1 levels and serum lipid profile were also assessed. The endothelial function was studied by flow-mediated dilation on the brachial artery, and arterial structure was evaluated by intima-media thickness measurement using Doppler ultrasound of both common carotid arteries.A significant (P < 0.05) difference in flow-mediated dilation (14.3 +/- 1.9% vs. 18.1 +/- 2.0% for PCOS patients and controls, respectively) and in intima-media thickness (0.53 +/- 0.09 mm vs. 0.39 +/- 0.08 mm for PCOS patients and controls, respectively) was found between PCOS and control subjects. Serum endothelin-1 levels were also significantly (P < 0.05) higher in PCOS patients compared with controls (1.1 +/- 0.4 pmol/liter vs. 0.5 +/- 0.2 pmol/liter for PCOS patients and controls, respectively).In conclusion, our data show that young, normal-weight, nondyslipidemic, nonhypertensive women with PCOS have an early impairment of endothelial structure and function.
The Hubble constant (H 0) tension between Type Ia supernovae (SNe Ia) and Planck measurements ranges from 4 to 6σ. To investigate this tension, we estimate H 0 in the ΛCDM and w 0 w a CDM (cold dark matter) models by dividing the Pantheon sample, the largest compilation of SNe Ia, into 3, 4, 20, and 40 bins. We fit the extracted H 0 values with a function mimicking the redshift evolution: g ( z ) = H 0 ( z ) = H ˜ 0 / ( 1 + z ) α , where α indicates an evolutionary parameter and H ˜ 0 = H 0 at z = 0. We set the absolute magnitude of SNe Ia so that H 0 = 73.5 km s − 1 Mpc − 1 , and we fix fiducial values for Ω 0 m Λ CDM = 0.298 and Ω 0 m w 0 w a CDM = 0.308 . We find that H 0 evolves with redshift, showing a slowly decreasing trend, with α coefficients consistent with zero only from 1.2 to 2.0σ. Although the α coefficients are compatible with zero in 3σ, this however may affect cosmological results. We measure locally a variation of H 0 ( z = 0 ) − H 0 ( z = 1 ) = 0.4 km s − 1 Mpc − 1 in three and four bins. Extrapolating H 0 ( z ) to z = 1100, the redshift of the last scattering surface, we obtain values of H 0 compatible in 1σ with Planck measurements independent of the cosmological models and number of bins we investigated. Thus, we have reduced the H 0 tension in the range from 54% to 72% for both cosmological models. If the decreasing trend of H 0 ( z ) is real, it could be due to astrophysical selection effects or to modified gravity.
A 6-month course of metformin improves endothelial structure and function in young, normal-weight women with PCOS.
VF amount is associated with subclinical CVD in PCOS patients.
Background. The efficacy of risk model scores to predict venous thromboembolism (VTE) in ambulatory cancer patients is under investigation, aiming to stratify on an individual risk basis the subset of the cancer population that could mostly benefit from primary thromboprophylaxis. Materials and Methods. We prospectively assessed 843 patients with active cancers, collecting clinical and laboratory data. We screened all the patients with a duplex ultrasound (B-mode imaging and Doppler waveform analysis) of the upper and lower limbs to evaluate the right incidence of VTE (both asymptomatic and symptomatic). The efficacy of the existing Khorana risk model in preventing VTE was also explored in our population. Several risk factors associated with VTE were analyzed, leading to the construction of a risk model. The Fine and Gray model was used to account for death as a competing risk in the derivation of the new model.
The difference from 4 to 6 σ in the Hubble constant (H0) between the values observed with the local (Cepheids and Supernovae Ia, SNe Ia) and the high-z probes (Cosmic Microwave Background obtained by the Planck data) still challenges the astrophysics and cosmology community. Previous analysis has shown that there is an evolution in the Hubble constant that scales as f(z)=H0/(1+z)η, where H0 is H0(z=0) and η is the evolutionary parameter. Here, we investigate if this evolution still holds by using the SNe Ia gathered in the Pantheon sample and the Baryon Acoustic Oscillations. We assume H0=70kms−1Mpc−1 as the local value and divide the Pantheon into three bins ordered in increasing values of redshift. Similar to our previous analysis but varying two cosmological parameters contemporaneously (H0, Ω0m in the ΛCDM model and H0, wa in the w0waCDM model), for each bin we implement a Markov-Chain Monte Carlo analysis (MCMC) obtaining the value of H0 assuming Gaussian priors to restrict the parameters spaces to values we expect from our prior knowledge of the current cosmological models and to avoid phantom Dark Energy models with w<−1. Subsequently, the values of H0 are fitted with the model f(z). Our results show that a decreasing trend with η∼10−2 is still visible in this sample. The η coefficient reaches zero in 2.0 σ for the ΛCDM model up to 5.8 σ for w0waCDM model. This trend, if not due to statistical fluctuations, could be explained through a hidden astrophysical bias, such as the effect of stretch evolution, or it requires new theoretical models, a possible proposition is the modified gravity theories, f(R). This analysis is meant to further cast light on the evolution of H0 and it does not specifically focus on constraining the other parameters. This work is also a preparatory to understand how the combined probes still show an evolution of the H0 by redshift and what is the current status of simulations on GRB cosmology to obtain the uncertainties on the Ω0m comparable with the ones achieved through SNe Ia.
The Neil Gehrels Swift observatory observes gamma-ray burst (GRB) plateaus in X-rays. We test the reliability of the closure relations through the fireball model when dealing with GRB plateau emissions. We analyze 455 X-ray light curves collected by Swift from 2005 January until 2019 August for which the redshifts are either known or unknown using the phenomenological Willingale 2007 model. Using these fits, we analyze the emission mechanisms and astrophysical environments of these GRBs through the closure relations within the time interval of the plateau emission. Finally, we test the three-dimensional fundamental plane relation (Dainotti relation) which connects the prompt peak luminosity, the time at the end of the plateau (rest frame), and the luminosity at that time, for the GRBs with redshift, concerning groups determined by the closure relations. This allows us to check if the intrinsic scatter σint of any of these groups is reduced compared to previous literature. The most fulfilled environments for the electron spectral distribution, p > 2, are wind slow cooling (SC) and interstellar material (ISM) slow cooling for cases in which the parameter q, which indicates the flatness of the plateau emission and accounts for the energy injection, is 0 and 0.5, respectively, in cases with both known and unknown redshifts. We also find that for short GRBs all ISM environments with q = 0 have the smallest σint = 0.04 ± 0.15 in terms of the fundamental plane relation holding a probability of occurring by chance of p = 0.005. We have shown that the majority of GRBs presenting plateau emission fulfill the closure relations, including the energy injection, with a particular preference for the wind SC environment. The subsample of GRBs that fulfill the given relations can be used as possible standard candles and can suggest a way to reduce the intrinsic scatter of these studied relationships.
The relationships between arachidonic acid (AA) metabolism and chloride secretion were investigated in mucosal preparations of rabbit distal colon. Tissues displayed a significant cyclooxygenase activity already in nonstimulated conditions and incubation with exogenous AA and calcium ionophore A23187 produced a predominant prostaglandin F2 alpha (PGF2 alpha) profile [PGF2 alpha greater than PGE2 greater than thromboxane B2 (TxB2) greater than 6-keto-PGF1 alpha] as assessed by HPLC of tissue homogenates, whereas 5-hydroxy-6,8,11,14-eicosatetraenoic acid (5-HETE) was not detected in AA- or A23187-stimulated tissues. Radioimmunological assays showed that PGE2 synthesis was time dependent, plateaued at 10 min, and proceeded at rates 15-20 times over TxB2 and 6-keto-PGF1 alpha. Among the PGs produced by colonic mucosa, only PGE2 and, to a lower extent, PGF2 alpha were found to stimulate chloride secretion and cAMP synthesis. Pretreatment with 10 microM 5,8,11,14-eicosatetraynoic acid, a cyclo- and lipoxygenase inhibitor, prevented AA-induced chloride secretion and PG and cAMP synthesis with the same strength as the cyclooxygenase inhibitor indomethacin. No effects were found after preincubation with nordihydroguaiaretic acid, a lipoxygenase blocker with moderate cyclooxygenase inhibitory properties, and caffeic acid, a lipoxygenase inhibitor. 5-HETE (5 microM) had no effect on short-circuit currents (Isc) and chloride transport, but it significantly reduced the increase in Isc, chloride secretion, and PGE2 synthesis elicited by AA or A23187. Platelet-activating factor, reported to stimulate rabbit colon Isc through an indomethacin-sensitive pathway, was not detected at concentrations as low as 10(-10) M.
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