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81.
82.
Objectives I examined the relationship between paid maternity leave and maternal mental health among women returning to work within 12 weeks of childbirth, after 12 weeks, and those returning specifically to full-time work within 12 weeks of giving birth. Methods I used data from 3850 women who worked full-time before childbirth from the Early Childhood Longitudinal Study—Birth Cohort. I utilized propensity score matching techniques to address selection bias. Mental health was measured using the Center for Epidemiologic Studies Depression (CESD) scale, with high scores indicating greater depressive symptoms. Results Returning to work after giving birth provided psychological benefits to women who used to work full-time before childbirth. The average CESD score of women who returned to work was 0.15 standard deviation (p?<?0.01) lower than the average CESD score of all women who worked full-time before giving birth. Shorter leave, on the other hand, was associated with adverse effects on mental health. The average CESD score of women who returned within 12 weeks of giving birth was 0.13 standard deviation higher (p?<?0.05) than the average CESD score of all women who rejoined labor market within 9 months of giving birth. However, receipt of paid leave was associated with an improved mental health outcome. Among all women who returned to work within 12 weeks of childbirth, those women who received some paid leave had a 0.17 standard deviation (p?<?0.05) lower CESD score than the average CESD score. The result was stronger for women who returned to full-time work within 12 weeks of giving birth, with a 0.32 standard deviation (p?<?0.01) lower CESD score than the average CESD score. Conclusions The study revealed that the negative psychological effect of early return to work after giving birth was alleviated when women received paid leave.  相似文献   
83.
Any clinical intervention (e.g., coronary angioplasty, thrombolysis) used to reintroduce blood flow to an ischemic region of the myocardium is accompanied by a complex enzymatic cascade of reactions resulting in severe injury to the heart, termed myocardial ischemia/reperfusion (I/R) injury. In this study, we evaluated the ability of H-3010 (1-hydroxy-2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrole-3-carboxylic acid (2-(3,4-dimethoxyphenyl)-5-([2-(3,4-dimethoxyphenyl)ethyl]-methylamino)-2-isopropylpentyl)-amide), a pyrroline modification of verapamil (2-(3,4-dimethoxyphenyl)-5-[2-(3,4-dimethoxyphenyl)ethylmethyl-amino]-2-(1-methylethyl)pentanenitrile), to protect the heart against I/R-mediated injury. Isolated perfused rat hearts pretreated with verapamil and H-3010 were subjected to 30 min of global no-flow ischemia followed by 45 min of reperfusion. The recovery (expressed as a percentage of preischemic baseline) in contractile function (left ventricular developed pressure) of hearts subjected to I/R was significantly higher in hearts treated with H-3010 at 5 microM (51.0 +/- 6.4%) as well as at 50 microM (75.1 +/- 7.4%) as compared with verapamil at 5 microM (32.2 +/- 3.7%) or untreated control hearts (18.1 +/- 2.8%). Creatine kinase release was significantly attenuated in hearts treated with H-3010 (45.7 +/- 4.5 U/liter) as compared with untreated controls (131.5 +/- 6.4 U/liter). Similar trends were also observed for lactate dehydrogenase release as well. A marked reduction in percent area of infarction was observed in the H-3010 group (11.7 +/- 1.6%) compared with verapamil (25.1 +/- 2.9%) and control (41.3 +/- 1.9%) groups. Additional in vitro studies showed a marked decrease in reactive oxygen species generation with H-3010. In conclusion, our data clearly demonstrated that the verapamil derivative, H-3010, significantly decreased I/R-induced cardiac dysfunction. This can be attributed to the combined benefits of the pyrroline moiety (antioxidant) and the parent verapamil component (antiarrhythmic) in the protection of the heart from I/R-induced injury.  相似文献   
84.
OBJECTIVES: Glutathionyl haemoglobin (GS-Hb) belonging to the class of glutathionylated proteins has been investigated as a possible marker of oxidative stress in different chronic diseases. The purpose of this study was to examine whether glutathionyl haemoglobin can serve as an oxidative stress marker in non-diabetic chronic renal failure patients on different renal replacement therapies (RRT) through its quantitation, and characterization of the specific binding site of glutathione in haemoglobin molecule by mass spectrometric analysis. DESIGN AND METHODS: The study group consisted of non-diabetic chronic renal failure patients on renal replacement therapy (RRT): hemodialysis (HD), continuous ambulatory peritoneal dialysis (CAPD) and renal allograft transplant (Txp) patients. Haemoglobin samples of these subjects were analyzed by liquid chromatography electrospray ionization mass spectrometry for GS-Hb quantitation. Characterization of GS-Hb was done by tandem mass spectrometry. Levels of erythrocyte glutathione (GSH) and lipid peroxidation (as thiobarbituric acid reacting substances) were measured spectrophotometrically, while glycated haemoglobin (HbA1c) was measured by HPLC. RESULTS: GS-Hb levels were markedly elevated in the dialysis group and marginally in the transplant group as compared to the controls. GS-Hb levels correlated positively with lipid peroxidation and negatively with the erythrocyte glutathione levels in RRT groups indicating enhanced oxidative stress. De novo sequencing of the chymotryptic fragment of GS-Hb established that glutathione is attached to Cys-93 of the beta globin chain. Mass spectrometric quantitation of total glycated haemoglobin showed good agreement with HbA1c estimation by conventional HPLC method. CONCLUSIONS: Glutathionyl haemoglobin can serve as a clinical marker of oxidative stress in chronic debilitating therapies like RRT. Mass spectrometry provides a reliable analytical tool for quantitation and residue level characterization of different post-translational modifications of haemoglobin.  相似文献   
85.
86.
Cartilage is avascular with limited to no regenerative capacity, so its loss could be a challenge for reconstructive surgery. Current treatment options for damaged cartilage are also limited. In this aspect there is a tremendous need to develop an ideal cartilage-mimicking biomaterial that could repair maxillofacial defects. Considering this fact in this study we have prepared twelve silicone-based materials (using Silicone 40, 60, and 80) reinforced with hydroxyapatite, tri-calcium phosphate, and titanium dioxide which itself has proven their efficacy in several studies and able to complement the shortcomings of using silicones. Among the mechanical properties (Young’s modulus, tensile strength, percent elongation, and hardness), hardness of Silicone-40 showed similarities with goat ear (P > .05). Silicone peaks have been detected in FTIR. Both AFM morphology and SEM images of the samples confirmed more roughed surfaces. All the materials were nonhemolytic in hemocompatibility tests, but among the twelve materials S2, S3, S5, and S6 showed the least hemolysis. For all tested bacterial strains, adherence was lower on each material than that grown on the plain industrial silicone material which was used as a positive control. S2, S3, S5, and S6 samples were selected as the best based on mechanical characterizations, surface characterizations, in vitro hemocompatibility tests and bacterial adherence activity. So, outcomes of this present study would be promising when developing ideal cartilage-mimicking biocomposites and their emerging applications to treat maxillofacial defects due to cartilage damage.  相似文献   
87.
Skin tension may influence keloid scar behavior, development, and spreading, e.g., butterfly‐shaped keloid disease in the sternum. Here, we developed a three‐dimensional (3D) in vitro model to mimic in vivo tension and evaluate keloid fibroblast (KF) behavior and extracellular matrix synthesis under tension. In vivo skin tension measured in volunteers (n = 4) using 3D image photogrammetry enabled prediction of actual force (35 mN). A novel cell force monitor applied tension in a fibroblast‐populated 3D collagen lattice replicating the in vivo force. The effect of tension on keloid (n = 10) fibroblast (KF) and normal skin (n = 10) fibroblasts (NF) at set time points (6, 12, and 24 hours) was measured in Hsp27, PAI‐2, and α2β1 integrin, tension‐related genes demonstrating significant (p < 0.05) time‐dependent regulation of these genes in NF vs. KF with and without tension. KF showed higher (p < 0.05) proliferation post‐tension. Knockdown of all three genes in 24 and 48 hours with and without tension showed significant down‐regulation in NF vs. KF. Additionally, we show significant (p < 0.05) modification of the expression of extracellular matrix‐related genes post‐tension following down‐regulation of Hsp27, PAI‐2, or α2β1 integrin. Finally, we demonstrate significant alteration in NF compared with KF morphology following knockdown. In conclusion, this study shows induction of tension‐related genes expression following mechano‐regulation in KFs, with potential relevance to its development and therapy.  相似文献   
88.
SAP-1 is a low molecular weight cysteine protease inhibitor (CPI) which belongs to type-2 cystatins family. SAP-1 protein purified from human seminal plasma (HuSP) has been shown to inhibit cysteine and serine proteases and exhibit interesting biological properties, including high temperature and pH stability. Heparin is a naturally occurring glycosaminoglycan (with varied chain length) which interacts with a number of proteins and regulates multiple steps in different biological processes. As an anticoagulant, heparin enhances inhibition of thrombin by the serpin antithrombin III. Therefore, we have employed surface plasmon resonance (SPR) to improve our understanding of the binding interaction between heparin and SAP-1 (protease inhibitor). SPR data suggest that SAP-1 binds to heparin with a significant affinity (KD = 158 nm ). SPR solution competition studies using heparin oligosaccharides showed that the binding of SAP-1 to heparin is dependent on chain length. Large oligosaccharides show strong binding affinity for SAP-1. Further to get insight into the structural aspect of interactions between SAP-1 and heparin, we used modelled structure of the SAP-1 and docked with heparin and heparin-derived polysaccharides. The results suggest that a positively charged residue lysine plays important role in these interactions. Such information should improve our understanding of how heparin, present in the reproductive tract, regulates cystatins activity.  相似文献   
89.
A pyrrole-based rhodamine conjugate (CS-1) has been developed and characterized for the selective detection and quantification of 2′-deoxy-5-(hydroxymethyl)cytidine (5hmC) in human cancer cells with a simple chemosensing method.

A new chemosensor, CS-1, has been developed and characterized for the selective detection and quantification of 2′-deoxy-5-(hydroxymethyl)cytidine (5hmC) in human cancer cells.

2′-Deoxy-5-(hydroxymethyl)cytidine (5hmC) is found in both neuronal cells and embryonic stem cells. It is a modified pyrimidine and used to quantify DNA hydroxymethylation levels in biological samples1–3 as it is capable of producing interstrand cross-links in double-stranded DNA. It is produced through an enzymatic pathway carried out by the Ten-Eleven Translocation (TET1, TET2, TET3) enzymes, iron and 2-oxoglutarate dependent dioxygenase.4–7 In the DNA demethylation process, methylcytosine is converted to cytosine and generates 5hmC as an intermediate in the first step of this process which is then further oxidized to 5-formylcytosine (fC) and 5-carboxycytosine (caC) of very low levels compared to the cytosine level.8 Though the biological function of 5hmC in the mammalian genome is still not revealed, the presence of a hydroxymethyl group can regulate gene expression (switch ON & OFF). Reports say that in artificial DNA 5hmC is converted to unmodified cytosine when introduced into mammalian cells.9,10Levels of 5hmC substantially vary in different tissues and cells. It is found to be highest in the brain, particularly in nervous system and in moderate percentage in liver, colon, rectum and kidney tissues, whereas it is relatively low in lung and very low in breast and placenta.11,12 The percentage of 5hmC content is much less in cancer and tumor tissues compared to the healthy ones. The reason behind this loss is the absence of TET1, TET2, TET3, IDH1, or IDH2 mutations in most of the human cancer cells which means decrease of methylcytosine oxidation.13–15 This loss of 5hmC in cancer cells is being used as a diagnostic tool for the detection of early-stage of malignant disease. Few analytical methods16–19 such as glucosyltransferase assays, tungsten-based oxidation systems, and TET-assisted bisulfite sequencing (TAB-Seq) or oxidative bisulfite sequencing (oxBS-Seq) protocols are now developed to differentiate 5hmC from other nucleotide which are naturally occurred. There are also few methods such as liquid chromatography/tandem mass spectroscopy (LC/MS-MS), which determine the level of 5hmC in mammalian cancer cell.20–22 However, these procedures are highly toxic and expensive due to requirement of catalyzation through enzymes or heavy metal ion and these techniques require expertise, facilities, much time and costs even beyond standard DNA sequencing. As a result, these detection techniques are currently inappropriate for the high-throughput screening of genome-wide 5hmC levels (performance comparison is shown in Table S1, ESI).Among all reputed methods fluorescence detection method using chemosensors is significantly important due to its indispensable role in medicinal and biological applications.23–27 Chemosensors have been effectively explored to monitor biochemical processes and assays through in situ analysis in living systems and abiotic samples with much less time and cost.In this contribution we prepared and characterize (Scheme S1 and Fig. S1–S3, ESI) a pyrrole–rhodamine based chemosensor (CS-1) which shows efficient and selective fluorescence signal for 5hmC in aqueous medium (Scheme 1). A transparent single crystal of CS-1 (Fig. 1) was obtained by slow evaporation of the solvent from a solution of CS-1 in CH3CN. It crystallizes as monoclinic with space group P21/n (Fig. S4 and Table S2, ESI).Open in a separate windowScheme 15hmC-induced FRET OFF–ON mechanism of the chemosensor CS-1.Open in a separate windowFig. 1ORTEP diagram of CS-1 (ellipsoids are drawn at 40% probability level).Spectrophotometric and spectrofluorimetric titrations were carried out to understand the CS-1–5hmC interaction with 1 : 1 binding stoichiometry (Fig. S5, ESI) upon adding varying concentrations of 5hmC to a fixed concentration of CS-1 (1 μM) in aqueous medium at neutral pH. Upon the addition of increasing concentrations of the 5hmC, a clear absorption band (Ka = 4.47 × 105 M−1, Fig. S6, ESI) appeared to be centered at 556 nm with increasing intensity (Fig. 2a). On the other hand, for the fluorescence emission spectra of CS-1 (Fig. 2b), upon irradiation at 325 nm, an emission maxima at 390 nm was observed, which was attributed to the fluorescence emission from the donor unit i.e. the pyrrole moiety of CS-1. When 5hmC were added, due to rhodamine moiety CS-1 showed a 95-fold increase in fluorescence at 565 nm (Ka = 4.61 × 105 M−1, Fig. S7, ESI) with the detection limit of 8 nM (Fig. S8, ESI). The binding of 5hmC induces opening of the spirolactam ring in CS-1, inducing a shift of the emission spectrum. Subsequently, increased overlap between the emission of the energy-donor (pyrrole) and the absorption of the energy-acceptor (rhodamine) greatly enhances the intramolecular FRET process,28,29 producing an emission from the energy acceptor unit in CS-1.Open in a separate windowFig. 2(a) UV-vis absorption spectra of CS-1 (1 μM) upon gradual addition of 5hmC up to 1.2 equiv. in H2O–CH3CN (15 : 1, v/v) at neutral pH. (b) Fluorescence emission spectra of CS-1 (1 μM) upon addition of 1.2 equiv. of 5hmC in H2O–CH3CN (15 : 1, v/v) at neutral pH (λex = 325 nm).In order to establish the sensing selectivity of the chemosensor CS-1, parallel experimentations were carried out with other pyrimidine/purine derivatives such as 5-methylcytosine, cytosine, cytidine, thymine, uracil, 5-hydroxymethyluracil, adenine and guanine. Comparing with other pyrimidine/purine derivatives the abrupt fluorescence enhancement was found upon addition of 5hmC to CS-1 while others do not make any fluorescence changes under UV lamp (Fig. 3, lower panel). Furthermore, the prominent color change from colorless to deep pink allows 5hmC to be detected by naked eye (Fig. 3, upper panel). The above observation shows consistency with the fluorescence titration experiments where no such binding of CS-1 with other pyrimidine/purine derivatives was found (Fig. S9, ESI).Open in a separate windowFig. 3Visible color (top) and fluorescence changes (bottom) of CS-1 (1 μM) in aqueous medium upon addition of 1.2 equiv. of various pyrimidine/purine derivatives (λex = 325 nm) in H2O–CH3CN (15 : 1, v/v) at neutral pH.pH titration reveals that CS-1 becomes fluorescent below pH 5 due to the spirolactam ring opening of rhodamine. However, it is non-fluorescent at pH range of 5–13. Upon addition of 5hmC to CS-1 shows deep red fluorescence in the pH range of 5–8 (Fig. S10, ESI). Considering the biological application and the practical applicability of the chemosensor pH 7.4 has been preferred to accomplish all experiments successfully.In 1H NMR titration (Fig. S11, ESI), the most interesting feature is the continuous downfield shift of aromatic protons on the pyrrole moiety of CS-1 upon gradual addition of 5hmC. This may be explained as the decrease in electron density of the pyrrole moiety upon binding with 5hmC through hydrogen bonding. Xanthene protons to be shifted downfield upon spirolactam ring opening indicates the probe to coordinate with 5hmC and electrons are accumulated around 5hmC. In 13C NMR titration the spiro cycle carbon peak at 65 ppm was shifted to 138 ppm along with a little downfield shift of the aromatic region of CS-1 (Fig. S12, ESI). This coordination led to the spiro cycle opening and changes to the absorption and emission spectra, further evident by mass spectrometry (Fig. S13, ESI), which corroborates the stronger interaction of CS-1 with 5hmC.The experimental findings were validated by density functional theory (DFT) calculations using the 6-31G+(d,p) method basis set implemented at Gaussian 09 program. Energy optimization calculations presented the conformational changes at the spirolactam position of CS-1 while 5hmC takes part to accommodate a probe molecule. After CS-1–5hmC complexation the energy is minimized by 19.45 kcal from the chemosensor CS-1, indicating a stable complex structure (Fig. 4 and Table S3, ESI). This theoretical study strongly correlates the experimental findings.Open in a separate windowFig. 4Energy diagram showing the energy differences between CS-1 and CS-1–5hmC complex.The desirable features of CS-1 such as high sensitivity and high selectivity at physiological pH encouraged us to further evaluate the potential of the chemosensor for imaging 5hmC in live cells (Fig. 5). A549 cells (Human cancer cell A549, ATCC no. CCL-185) treated with CS-1 (1 μM) exhibited weak fluorescence, whereas a deep red fluorescence signal was observed in the cells stained with CS-1 (1 μM) and 5hmC (10 μM), which is in good agreement with the FRET OFF–ON profile of the chemosensor CS-1 in presence of 5hmC, thus corroborating the in-solution observation (Fig. S14, ESI). Cytotoxicity assay measurement shows that the chemosensor CS-1 does not have any toxicity on the tested cells and CS-1–5hmC complex does not exert any significant adverse effect on cell viability at tested concentrations (Fig. S15, ESI). As far as we are aware, this is the first report where we are executing the possible use of the pyrrole–rhodamine based chemosensor for selective recognition of 5hmC in living cells. These findings open an avenue for future biomedical applications of the chemosensor to recognize 5hmC.Open in a separate windowFig. 5Confocal microscopic images of A549 cells treated with CS-1 and 5hmC. (a) Cells treated with only CS-1 at 1 μM concentration. (b) Bright field image of (a). (c) Cells treated with CS-1 and 5hmC at concentration 10 μM. (d) Bright field image of (c). All images were acquired with a 60× objective lens with the applied wavelengths: For (a) and (b), Eex = 341 nm, Eem = 414 nm, filter used: DIDS; for (c) and (d) Eex = 550 nm, Eem = 571 nm, filter used: Rhod-2.The concentration of 5hmC was also quantified from A549 human cancer cells. Lysate of 107 A549 cells was added to 1 μM of CS-1 and the fluorescence signal was recorded. Presence of 5hmC in these cancer cells was detected with the help of CS-1–5hmC standard fluorescence curve (Fig. 6) using the selective detection ability of the chemosensor CS-1.Open in a separate windowFig. 6(a) Calibration curve obtained for the estimation of 5hmC. (b) Estimation of the concentration of 5hmC (red point) from the calibration curve.From the standard curve it was found that the concentration of 5hmC in the tested sample was 0.034 μM present in 16.7 mm3 A549 cell volume (). Assay of 5hmC was further validated from multiple samples of A549 human cancer cells using CS-1. Increasing fold of fluorescence signals was also statistically validated after calculating the Z′ value (Table S5, ESI). All tested samples shows the Z′ score value more than 0.9, indicating an optimized and validated assay of 5hmC.Quantification of 5hmC in human cancer cell A549
SampleCS-1 used (μM)Initial 5hmC usedAddition of exogenous 5hmC (μM)Amount of 5hmC derived from fluorescence signal (μM)Fluorescence signal recovery (%)
115hmC present in 16.7 mm3 A549 cell volume00.034
2111.02899.4
3134.01999.6
4155.01299.5
Open in a separate window  相似文献   
90.
OBJECTIVE: Leishmanial lipid is a strong immunosuppressor of host cells. Inhibition of the inflammatory responses of synovial cells through induction of apoptosis is one of the main targets of therapeutic intervention in rheumatoid arthritis (RA). This study was undertaken to examine the antiinflammatory and apoptosis-inducing effects of leishmanial lipid on adherent synovial fluid mononuclear cells (SFMCs) in patients with RA. METHODS: Lipid was extracted from a Leishmania donovani promastigote (MHO/IN/1978/UR6) by the Bligh and Dyer method. Nitric oxide (NO) was measured using the Griess reaction, and enzyme-linked immunosorbent assays for cytokines, NF-kappaB, and cytochrome c were performed. Levels of cytokines, inducible nitric oxide synthase, caspases, Bcl-2, Bax, t-Bid, and cytochrome c in the cell lysate and of NF-kappaB p65 in the nucleus were determined by Western blotting. Microscopic analysis, nuclear staining, DNA fragmentation assay, fluorescence-activated cell sorting, colorimetric assay for caspases, and fluorescent probe for measurement of mitochondrial membrane potential were used to study the leishmanial lipid-induced apoptotic pathway in SFMCs. RESULTS: Leishmanial lipid inhibited the release of tumor necrosis factor alpha, interleukin-1beta, and NO in the culture, decreased their cytosolic protein levels, and decreased NF-kappaB p65 levels in SFMCs, in a dose-dependent manner. It had the reverse effect on interleukin-10 levels. Leishmanial lipid-induced apoptosis involved the activation of caspase 3, caspase 9, and Bax, the release of cytochrome c, the alteration of mitochondrial membrane potential, and the down-regulation of Bcl-2. CONCLUSION: These results suggest that leishmanial lipid has strong antiinflammatory and apoptosis-inducing effects on SFMCs from patients with RA, and that apoptosis occurs via the mitochondrial pathway.  相似文献   
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