N-Alkylation and N-acylation of the prostaglandin-F2α allosteric modulator l-PDC31 were performed to install various alkyl, PEG and isoprenoid groups onto the l-enantiomer of the peptide. Among the different bio-conjugates studied, the N-dodecyl analog reduced prostaglandin-F2α-induced mouse myometrium contractions ex vivo. Furthermore, N-dodecyl-l-PDC31 exhibited improved stability in a mouse serum assay, likely due to protection from protease degradation by the lipid chain.
Diffusion kurtosis imaging (DKI), an extension of diffusion tensor imaging (DTI), provides a practical method to describe non-Gaussian water diffusion in neural tissues. The sensitivity of DKI to detect the subtle changes in several chosen brain structures has been studied. However, intuitive and holistic methods to validate the merits of DKI remain to be explored. In this paper, tract-based spatial statistics (TBSS) was used to demonstrate white matter alterations in both DKI and DTI parameters in preschool children (1-6 years; n=10). Correlation analysis was also performed in multiple regions of interest (ROIs). Fractional anisotropy, mean kurtosis, axial kurtosis and radial kurtosis increased with age, while mean diffusivity and radial diffusivity decreased significantly with age. Fractional anisotropy of kurtosis and axial diffusivity were found to be less sensitive to the changes with age. These preliminary findings indicated that TBSS could be used to detect subtle changes of DKI parameters on the white matter tract. Kurtosis parameters, except fractional anisotropy of kurtosis, demonstrated higher sensitivity than DTI parameters. TBSS may be a convenient method to yield higher sensitivity of DKI.
Microvascular degeneration is an important event in oxygen-induced retinopathy (OIR), a model of retinopathy of prematurity. Because oxidant stress abundantly generates thromboxane A 2 (TxA 2 ), we tested whether TxA 2 plays a role in retinal vasoobliteration of OIR and contributes to such vascular degeneration by direct endothelial cytotoxicity. Hyperoxia-induced retinal vasoobliteration in rat pups (80% O 2 exposure from postnatal days 5–14) was associated with increased TxB 2 generation and was significantly prevented by TxA 2 synthase inhibitor CGS-12970 (10 mg · kg −1 · day −1 ) or TxA 2 -receptor antagonist CGS-22652 (10 mg · kg −1 · day −1 ). TxA 2 mimetics U-46619 (EC 50 50 nM) and I-BOP (EC 50 5 nM) caused a time- and concentration-dependent cell death of neuroretinovascular endothelial cells from rats as well as newborn pigs but not of smooth muscle and astroglial cells; other prostanoids did not cause cell death. The peroxidation product 8-iso-PGF 2 , which is generated in OIR, stimulated TxA 2 formation by endothelial cells and triggered cell death; these effects were markedly diminished by CGS-12970. TxA 2 -dependent neuroretinovascular endothelial cell death was mostly by necrosis and to a lesser extent by apoptosis. The data identify an important role for TxA 2 in vasoobliteration of OIR and unveil a so far unknown function for TxA 2 in directly triggering neuroretinal microvascular endothelial cell death. These effects of TxA 2 might participate in other ischemic neurovascular injuries.
Recent clinical studies have demonstrated the suppressive effect of selenium (Se) treatment on serum thyroid-specific antibody titers in patients with autoimmune thyroiditis (AIT), but the mechanism underlying this process is not clear. The aim of the present study was to investigate the effects of selenium on the incidence and severity of AIT, titers of thyroid autoantibodies, and selenoprotein expression in thyroid in a spontaneous autoimmune thyroiditis (SAT) model.NOD.H-2(h4) mice at four weeks of age were randomly divided into control, iodine supplement (SAT), and selenium supplement groups (SAT+Se). Mice were given 0.005% sodium iodide water for eight weeks to induce SAT and then 0.3 mg/L sodium selenite in drinking water for 8 weeks and 16 weeks. The severity of lymphocytic infiltration in the thyroid, serum thyroglobulin antibody (TgAb) titers, serum selenium concentration, expression of glutathione peroxidase-1 (GPx1), thioredoxin reductase-1 (Txnrd1), and peroxiredoxin 5 were measured.Serum selenium concentration significantly increased after selenium supplementation. Serum TgAb levels were significantly lower in the selenium group compared with the SAT group (p<0.05). The prevalence of thyroiditis and the degree of infiltration of lymphocytes decreased gradually over time in the group provided with selenium supplementation. The expression of GPx1 and Txnrd1 by Western blotting were found to be significantly higher in the SAT+Se group than in other groups (p<0.05).These results indicate that selenium treatment can increase the function of antioxidation by upregulating the expression of selenoproteins in the thyroid and have an inhibitory effect on TgAb titers, which may have an impact on AIT.
Objective: The use of antithyroid drugs (ATDs) carries potential risk for teratogenic effects. For women with well-controlled hyperthyroidism on a low dose of ATDs, drug withdrawal upon pregnancy is recommended by international medical guidelines. Therefore, it is necessary to determine the characteristics of patients suitable for ATD withdrawal, subsequent changes in thyroid function after ATD discontinuation, and its impact on pregnancy and offspring outcomes. Methods: This prospective study recruited 63 pregnant women with well-controlled Graves' hyperthyroidism who had stopped ATDs during early pregnancy. Patients were followed up until the end of pregnancy and data on pregnancy outcomes were collected. Results: Overall, 20 patients (31.7%) had rebound of hyperthyroidism. Patients with either subnormal thyrotropin (TSH) levels (TSH <0.35 mIU/L, odds ratio [OR] = 5.12, confidence interval [CI = 1.29-20.34], p = 0.03) or positive thyrotropin receptor antibody (TRAb) (TRAb >1.75 IU/L, OR = 3.79, [CI = 1.17-12.30], p = 0.02) at the time of ATDs withdrawal presented a higher risk of rebound than those with either normal TSH levels or negative TRAb. Patients with both subnormal TSH and positive TRAb at the time of ATD withdrawal were more likely to experience rebound (83.3%, 5/6) than those with both normal TSH and negative TRAb (13%, 3/23, OR = 33.33, [CI = 2.83-392.60], p = 0.003). The prevalence of adverse pregnancy outcomes was significantly higher in patients who experienced rebound compared with those who did not (55.0% vs. 9.3%, OR = 11.92, [CI = 3.08-46.18], p = 0.0002). Conclusions: Subnormal TSH levels and TRAb positivity at the time of ATD withdrawal in early pregnancy may be associated with rebound of Graves' hyperthyroidism. Rebound of hyperthyroidism during pregnancy may increase the risk of adverse pregnancy outcomes. Larger prospective studies are needed to confirm these findings.
Stimulation of freshly isolated rat hepatocytes with lysophosphatidic acid (LPA) resulted in LPA1 receptor-mediated and nitricoxide-dependent up-regulation of the immediate early genes iNOS (inducible nitric-oxide synthase (NOS)) and mPGES-1 (microsomal prostaglandin E synthase-1). Because LPA is a ligand for both cell surface and intracellular receptor sites and a potent endothelial NOS (eNOS) activator, we hypothesized that NO derived from activated nuclearized eNOS might participate in gene regulation. Herein we show, by confocal microscopy performed on porcine cerebral endothelial cells expressing native LPA1-receptor and eNOS and on HTC4 rat hepatoma cells co-transfected with recombinant human LPA1-receptor and fused eNOS-GFP cDNA, a dynamic eNOS translocation from peripheral to nuclear regions upon stimulation with LPA. Nuclear localization of eNOS and its downstream effector, soluble guanylate cyclase, were demonstrated in situ in rat liver specimens by immunogold labeling using specific antibodies. Stimulation of this nuclear fraction with LPA and the NO donor sodium nitroprusside resulted, respectively, in increased production of nitrite (and eNOS phosphorylation) and cGMP; these separate responses were also correspondingly blocked by NOS inhibitor L-NAME and soluble guanylate cyclase inhibitor ODQ. In addition, sodium nitroprusside evoked a sequential increase in nuclear Ca2+ transients, activation of p42 MAPK, NF-kappaB binding to DNA consensus sequence, and dependent iNOS RNA. This study describes a hitherto unrecognized molecular mechanism by which nuclear eNOS through ensuing NO modulates nuclear calcium homeostasis involved in gene transcription-associated events. Moreover, our findings strongly support the concept of the nucleus as an autonomous signaling compartment.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
