Rumen-protected conjugated linoleic acid (CLA) reportedly improves fertility in lactating dairy cows by reducing the postpartum interval to first ovulation and enhancing the circulating insulin-like ...growth factor-I (IGF-I) levels. The objectives of this study were to evaluate the blood metabolites, hormones, follicular fluid (FF) and liver for the effect of CLA supplementation (50 g top-dressed daily from 15 days pre-partum to 65 days in milk -DIM -). Pre-partum Holstein cows (n = 24) were assigned to two treatments: a Control and CLA group (n = 12 cows/group). Dry matter intake (DMI) and milk production were recorded daily. At 26 DIM, ovulation was synchronized and at 34 DIM, plasma and FF were analysed for paraoxonase 1(PON) levels. Moreover plasma was analysed for IGF binding protein 2 and 3 (IGFBP). From 34 DIM, blood samples and FF from follicles >9 mm were collected and analysed for estradiol, progesterone, IGF-I and lipoproteins. A liver biopsy was performed at 65 DIM and analysed for the expression of IGF-I, growth hormone receptor (GHR), pyruvate carboxylase (PC) and cytosolic phosphoenolpyruvate carboxykinase (PECK). CLA supplemented cows, compared to the control group, recorded a significant lower milk fat production, improved DMI and energy balance and recorded significant increased plasma concentrations of IGF-I, cholesterol, low density lipoprotein (LDL) and IGFBP-3 (interaction treatment x DIM). The concentration of IGF-I, high density lipoprotein (HDL) and LDL tended to be higher in FF than plasma. This study confirms the positive effects of dietary CLA supplementation on the metabolism, by improving the energy intake and reducing the negative energy balance. Moreover, the improvement of plasma IGF-I levels observed in this study, coupled with a better energy balance support previous studies showing a positive effect of CLA supplementation on reproduction. However, CLA did not alter the plasma and the FF concentration of PON, nor the liver gene expression.
The effect of L-ascorbate on the binding of 14Cacetaldehyde to bovine serum albumin was examined. In the absence of ascorbate, acetaldehyde reacted with albumin to form both unstable (Schiff bases) ...and stable adducts. Ascorbate (5 mM) caused a time-dependent increase in the formation of total acetaldehyde-albumin adducts, which were comprised mainly of stable adducts. Significant enhancement of adduct formation by ascorbate was observed at acetaldehyde concentrations as low as 5 microM. An ascorbate concentration as low as 0.5 mM was still effective in stimulating stable adduct formation. The electron acceptor, 2,6 dichlorophenolindophenol, prevented the ascorbate-induced increase in albumin-adduct formation. Ascorbate also caused enhanced acetaldehyde adduct formation with other purified proteins, including cytochrome c and histones, as well as the polyamino acid, poly-L-lysine. These results indicate that ascorbate, acting as a reducing agent, can convert unstable acetaldehyde adducts to stable adducts, and can thereby increase and stabilize the binding of acetaldehyde to proteins.
Acetaldehyde production and the radiolabeling of hepatic proteins were determined in rat liver slices incubated with 14C-ethanol (10 mmol/L). Significant labeling of hepatic proteins occurred in the ...presence of protein synthesis inhibitors, indicating that, under these conditions, the radiolabeling of protein did not occur via de novo protein synthesis. Additional experiments indicated that the major source of protein-bound radioactivity derived from 14C-ethanol oxidation was the formation of 14C-acetaldehyde adducts with proteins. This conclusion was made from observations that pyrazole, an inhibitor of ethanol oxidation and, therefore, acetaldehyde formation, decreased radiolabeling of protein, whereas cyanamide, which elevated hepatic acetaldehyde levels, markedly increased the labeling of protein. Furthermore, L-cysteine, which can bind acetaldehyde and, therefore, act as an acetaldehyde trap, substantially reduced protein-bound radioactivity. It was also demonstrated that acetaldehyde formed both stable and unstable adducts with hepatic proteins and that unstable adducts may undergo conversion to form stable adducts during incubation.
Abstract
We present the discovery of DELVE 6, an ultra-faint stellar system identified in the second data release of the DECam Local Volume Exploration (DELVE) survey. Based on a maximum-likelihood ...fit to its structure and stellar population, we find that DELVE 6 is an old (
τ
> 9.8 Gyr at 95% confidence) and metal-poor (Fe/H < −1.17 dex at 95% confidence) stellar system with an absolute magnitude of
M
V
=
−
1.5
−
0.6
+
0.4
mag and an azimuthally averaged half-light radius of
r
1
/
2
=
10
−
3
+
4
pc. These properties are consistent with the population of ultra-faint star clusters uncovered by recent surveys. Interestingly, DELVE 6 is located at an angular separation of ∼10° from the center of the Small Magellanic Cloud (SMC), corresponding to a 3D physical separation of ∼20 kpc given the system’s observed distance (
D
⊙
= 80 kpc). This also places the system ∼35 kpc from the center of the Large Magellanic Cloud (LMC), lying within recent constraints on the size of the LMC’s dark matter halo. We tentatively measure the proper motion of DELVE 6 using data from Gaia, which we find supports a potential association between the system and the LMC/SMC. Although future kinematic measurements will be necessary to determine its origins, we highlight that DELVE 6 may represent only the second or third ancient (
τ
> 9 Gyr) star cluster associated with the SMC, or one of fewer than two dozen ancient clusters associated with the LMC. Nonetheless, we cannot currently rule out the possibility that the system is a distant Milky Way halo star cluster.
•PVA/iron oxide milli-size beads were synthesized by means of a one-pot route.•Effective demagnetizing factor (NE) is tested in beads and superstructures of beads.•The increase of the ac ...susceptibility as a function of hydration agrees with the diminution of dipolar interactions.•Isothermal magnetization experiments are described by considering two hierarchies of clustering.•The NE proves to be an efficient tool for the analysis of complex 3d dispersions of magnetic nanoparticles.
The recently published Mean Field Interacting Superparamagnet Model (MFISP model), which introduces the effective demagnetizing factor NE, is tested in specimens having a random-like spatial distribution of magnetic nanoparticles, where different hierarchies of clustering are present. These specimens are ferrogel PVA/iron oxide beads synthesized by a one-pot route, having spheroidal shapes and sizes of about 1 mm, and chain and disk-like arrays (superstructures) of beads. Raman analyses indicated that magnetic nanoparticles are composed by a mixture of magnetite and maghemite. Beads swell 208% by hydration in about 40 min.
The increase of the ac susceptibility as a function of hydration time closely reflects the effect of bead swelling, in agreement with the expected diminution of dipole–dipole interactions. Measured susceptibility is analyzed in terms of the susceptibility χ of non-interacting particles and the effective demagnetizing factor NE of the specimen, which depends on swelling. The Specific Absorption Rate of electromagnetic power by the beads grows with the hydration time in agreement with ac susceptibility behavior.
For long hydration times susceptibility and high field magnetization decrease. This is explained by the occurrence of oxidation of magnetite/maghemite to hematite.
Isothermal magnetization experiments are performed on each superstructure in two perpendicular principal directions each. Results are consistently described with the MFISP model by considering two hierarchies of clustering: beads themselves and clusters within the beads.
From the whole set of experiments, it is possible to estimate values for the volume fractions of particles in clusters and clusters in beads, given by xpc=0.46(15) and xcb=0.16(5). The susceptibility of non-interacting particles, χ=13(4), is also obtained, which results about five times larger than the measured (apparent) one.
The MFISP model proves to be a convenient and efficient tool for the analysis of magnetization studies of complex 3d dispersions of magnetic nanoparticles, allowing an experimental determination of relevant physical information, otherwise not accessible by magnetic measurements.
Accumulated evidence suggests that an abnormal placentation and an altered expression of a variety of trophoblast transporters are associated to preeclampsia. In this regard, an abnormal expression ...of AQP3 and AQP9 was reported in these placentas. Recent data suggests that placental AQPs are not only water channel proteins and that may participate in relevant processes required for a normal placental development, such as cell migration and apoptosis. Recently we reported that a normal expression of AQP3 is required for the migration of extravillous trophoblast (EVT) cells. Thus, alterations in this protein might lead to an insufficient transformation of the maternal spiral arteries resulting in fluctuations of oxygen tension, a potent stimulus for oxidative damage and trophoblast apoptosis. In this context, the increase of oxygen and nitrogen reactive species could nitrate AQP9, producing the accumulation of a non-functional protein affecting the survival of the villous trophoblast (VT). This may trigger the exacerbated release of apoptotic VT fragments into maternal circulation producing the systemic endothelial dysfunction underlying the maternal syndrome. Therefore, our hypothesis is that the alteration in the expression of placental AQPs observed at the end of gestation may take place during the trophoblast stem cell differentiation, disturbing both EVT and VT cells development, or during the VT differentiation and turnover. In both situations, VT is affected and at last the maternal vascular system is activated leading to the clinical manifestations of preeclampsia.
Background
Hydrocephalus is a common neurological disorder, caused by a progressive accumulation of cerebrospinal fluid (CSF) within the intracranial space that can lead to increased intracranial ...pressure, enlargement of the ventricles (ventriculomegaly) and, consequently, to brain damage. Ventriculo‐peritoneal shunt systems are the mainstay therapy for this condition, however there are different types of shunt systems.
Objectives
To compare the effectiveness and adverse effects of conventional and complex shunt devices for CSF diversion in people with hydrocephalus.
Search methods
We searched the Cochrane Central Register of Controlled Trials (2020 Issue 2); Ovid MEDLINE (1946 to February 2020); Embase (Elsevier) (1974 to February 2020); Latin American and Caribbean Health Science Information Database (LILACS) (1980 to February 2020); ClinicalTrials.gov; and World Health Organization International Clinical Trials Registry Platform.
Selection criteria
We selected randomised controlled trials or quasi‐randomised trials of different types of ventriculo‐peritoneal shunting devices for people with hydrocephalus. Primary outcomes included: treatment failure, adverse events and mortality.
Data collection and analysis
Two review authors screened studies for selection, assessed risk of bias and extracted data. Due to the scarcity of data, we performed a Synthesis Without Meta‐analysis (SWiM) incorporating GRADE for the quality of the evidence.
Main results
We included six studies with 962 participants assessing the effects of standard valves compared to anti‐syphon valves, other types of standard valves, self‐adjusting CSF flow‐regulating valves and external differential programmable pressure valves. All included studies started in a hospital setting and offered ambulatory follow‐up. Most studies were conducted in infants or children with hydrocephalus from diverse causes. The certainty of the evidence for most comparisons was low to very low.
1. Standard valve versus anti‐syphon valve
Three studies with 296 randomised participants were included under this comparison. We are uncertain about the incidence of treatment failure in participants with standard valve and anti‐syphon valves (very low certainty of the evidence). The incidence of adverse events may be similar in those with standard valves (range 0 to 1.9%) and anti‐syphon valves (range 0 to 2.9%) (low certainty of the evidence). Mortality may be similar in those with standard valves (0%) and anti‐syphon valves (0.9%) (RD 0.01%, 95% CI ‐0.02% to 0.03%, low certainty of the evidence). Ventricular size and head circumference may be similar in those with standard valves and anti‐syphon valves (low certainty of the evidence). None of the included studies reported the quality of life of participants.
2. Comparison between different types of standard valves
Two studies with 174 randomised participants were included under this comparison. We are uncertain about the incidence of treatment failure in participants with different types of standard valves (early postoperative period: RR 0.41, 95% CI 0.13 to 1.27; at 12 months follow‐up: RR 1.17, 95% CI 0.72 to 1.92, very low certainty of the evidence). None of the included studies reported adverse events beyond those included under "treatment failure". We are uncertain about the effects of different types of standard valves on mortality (range 2% to 17%, very low certainty of the evidence). The included studies did not report the effects of these interventions on quality of life, ventricular size reduction or head circumference.
3. Standard valve versus self‐adjusting CSF flow‐regulating valve
One study with 229 randomised participants addressed this comparison. The incidence of treatment failure may be similar in those with standard valves (42.98%) and self‐adjusting CSF flow‐regulating valves (39.13%) (low certainty of the evidence). The incidence of adverse events may be similar in those with standard valves (range 0 to 1.9%) and those with self‐adjusting CSF flow‐regulating valves (range 0 to 7.2%) (low certainty of the evidence). The included study reported no deaths in either group in the postoperative period. Beyond the early postoperative period, the authors stated that nine patients died (no disaggregated data by each type of intervention was available, low certainty of the evidence). The included studies did not report the effects of these interventions on quality of life, ventricular size reduction or head circumference.
4. External differential programmable pressure valve versus non‐programmable valve
One study with 377 randomised participants addressed this comparison. The incidence of treatment failure may be similar in those with programmable valves (52%) and non‐programmable valves (52%) (RR 1.02, 95% CI 0.84 to 1.24, low certainty of the evidence). The incidence of adverse events may be similar in those with programmable valves (6.19%) and non‐programmable valves (6.01%) (RR 0.97, 95% CI 0.44 to 2.15, low certainty of the evidence). The included study did not report the effect of these interventions on mortality, quality of life or head circumference. Ventricular size reduction may be similar in those with programmable valves and non‐programmable valves (low certainty of the evidence).
Authors' conclusions
Standard shunt valves for hydrocephalus compared to anti‐syphon or self‐adjusting CSF flow‐regulating valves may cause little to no difference on the main outcomes of this review, however we are very uncertain due to the low to very low certainty of evidence. Similarly, different types of standard valves and external differential programmable pressure valves versus non‐programmable valves may be associated with similar outcomes. Nevertheless, this review did not include valves with the latest technology, for which we need high‐quality randomised controlled trials focusing on patient‐important outcomes including costs.
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