Alcohol and maternal uterine vascular adaptations during pregnancy-part I: effects of chronic in vitro binge-like alcohol on uterine endothelial nitric oxide system and function

Background: Pregnancy‐induced utero‐placental growth, angiogenic remodeling, and enhanced vasodilation are all partly regulated by estradiol‐17β‐mediated activation of endothelial nitric oxide synthase (eNOS) and nitric oxide (NO) production. However, very little is known about the effects of alcohol on these maternal utero‐placental vascular adaptations during pregnancy and its potential role in the pathogenesis of fetal alcohol spectrum disorders (FASDs). In this study, we hypothesized that in vitro chronic binge‐like alcohol will decrease uterine arterial endothelial eNOS expression and alter its multisite phosphorylation activity state via disruption of AKT signaling. To study the direct effects of alcohol on uterine vascular adaptations, we further investigated the effects of alcohol on estradiol‐17β‐induced uterine angiogenesis in vitro. Methods: Uterine artery endothelial cells were isolated from pregnant ewes (gestational day 120 to 130; term = 147), fluorescence‐activated cell sorted, validated, and maintained in culture to passage 4. To mimic maternal binge drinking patterns, cells were cultured in the absence or presence of a lower (LD) or higher dose (HD) of alcohol in a compensating sealed humidified chamber system equilibrated with aqueous alcohol for 3 hours on 3 consecutive days. Immunoblotting was performed to assess expression of NO system‐associated proteins and eNOS multi‐site phosphorylation. Following this treatment paradigm, control and binge alcohol‐treated cells were passaged, grown for 2 days, and then treated with increasing concentrations of estradiol‐17β (0.1, 1, 10, 100 nM) in the absence or presence of LD or HD alcohol to evaluate estradiol‐17β‐induced angiogenesis index using BrdU proliferation assay. Results: LD and HD binge‐like alcohol decreased uterine arterial eNOS expression (p = 0.009). eNOS multisite phosphorylation activation state was altered: P⁶³⁵eNOS was decreased (p = 0.017), P¹¹⁷⁷eNOS was not altered, and P⁴⁹⁵eNOS exhibited an inverse U‐shaped dose‐dependent relationship with alcohol. LD and HD alcohol decreased the major eNOS‐associated protein cav‐1 (p < 0.001). However, the commonly implicated AKT pathway did not correlate with eNOS posttranslational modifications. Assessment of uterine vascular adaptation via angiogenesis demonstrated that alcohol abrogated the dose‐dependent proliferative effects of estradiol‐17β and thus blunted angiogenesis. Conclusions: Thus, the maternal uterine vasculature during pregnancy may be vulnerable to chronic binge‐like alcohol. Altered eNOS multisite phosphorylation also suggests that alcohol produces specific effects at the level of posttranslational modifications critical for pregnancy‐induced uterine vascular adaptations. Finally, the alcohol and estradiol‐17β data suggest a negative impact of alcohol on estrogen actions on the uterine vasculature.     

Safety of regadenoson in patients with end-stage liver disease

Background

Regadenoson is a selective A_2A receptor agonist that is used for vasodilator stress myocardial perfusion imaging (MPI). Since the drug is partially metabolized by the liver, its safety in patients with end-stage liver disease (ESLD) needs to be determined.

Methods and Results

We studied 168 consecutive patients with ESLD who had regadenoson stress gated single photon emission computed tomography MPI between January 2008 and March 2010 before planned orthotopic liver transplantation and compared the hemodynamic responses and safety profile to 168 control patients. There were 72 women (43%) in ESLD versus 87 (52%) in the control group (P = .1). The patients with ESLD were younger (58 ± 7 vs 62 ± 12 years, P = .0002), but more likely to be Caucasians (P = .002). The MPI images were normal in 161 patients (96%) in each group. The left ventricular ejection fraction was 72 ± 10% in ESLD and 66 ± 11% in the control patients (P = .0001). The heart rate increase in response to regadenoson was lower in patients with ESLD than in the control group (16 ± 11 vs 23 ± 16 bpm, P = .0001), but the changes in systolic and diastolic blood pressures were similar (?9 ± 12 vs ?11 ± 14 mmHg and ?6 ± 8 vs ?7 ± 10 mmHg, respectively, P = NS). There were no deaths or medication-related adverse events that required hospitalization in either group within 30 days of the study.

Conclusion

This is the first study to document the tolerability and safety profile of regadenoson in patients with ESLD.     

Evaluation of hepatoprotective activity of Kyllinga nemoralis (Hutch & Dalz) rhizomes

Aim of study

In view of the use of rhizomes of Kyllinga nemoralis L., against hepatopathy in ethnomedicine the present study was aimed at evaluating the hepatoprotective activity of the rhizomes of Kyllinga nemoralis against carbon tetrachloride (CCl₄)-induced hepatotoxicity in rats.

Materials and methods

Hepatotoxicity was induced in male Wistar rats by carbon tetrachloride and olive oil (50%, v/v). i.p. ethanolic and petroleum ether extracts of Kyllinga nemoralis rhizomes were administered to the experimental rats (100 and 200 mg/kg, p.o. for seven days). The hepatoprotective effect of these extracts was evaluated by the assay of liver function biochemical parameters and histopathological studies of the liver compared with silymarin.

Results

Both extracts showed significant hepatoprotection when compared to control, similar to standard silymarin. Histology of liver sections also revealed that the extracts protected liver from injury.

Conclusions

The study identified a plant with potential hepatoprotective constituents which will be isolated and characterized in future.     

Highly loaded, sustained-release microparticles of curcumin for chemoprevention

Curcumin, a dietary polyphenol, has preventive and therapeutic potential against several diseases. Because of the chronic nature of many of these diseases, sustained-release dosage forms of curcumin could be of significant clinical value. However, extreme lipophilicity and instability of curcumin are significant challenges in its formulation development. The objectives of this study were to fabricate an injectable microparticle formulation that can sustain curcumin release over a 1-month period and to determine its chemopreventive activity in a mouse model. Microparticles were fabricated using poly(D, L-lactide-co-glycolide) polymer. Conventional emulsion solvent evaporation method of preparing microparticles resulted in crystallization of curcumin outside of microparticles and poor entrapment (～1%, w/w loading). Rapid solvent removal using vacuum dramatically increased drug entrapment (～38%, w/w loading; 76% encapsulation efficiency). Microparticles sustained curcumin release over 4 weeks in vitro, and drug release rate could be modulated by varying the polymer molecular weight and/or composition. A single subcutaneous dose of microparticles sustained curcumin liver concentration for nearly a month in mice. Hepatic glutathione-s-transferase and cyclooxygenase-2 activities, biomarkers for chemoprevention, were altered following treatment with curcumin microparticles. The results of these studies suggest that sustained-release microparticles of curcumin could be a novel and effective approach for cancer chemoprevention.     

Human primary cultured hepatic stellate cells can be cryopreserved

We compared the morphological and functional characteristics of cultured unfrozen hepatic stellate cells (HSCs) and cryopreserved HSCs obtained from human livers. We used liver tissues obtained by surgical resection from patients with metastatic liver cancer or with hepatocellular carcinoma. HSCs were isolated and allowed to spread in culture. Comparison of morphological and functional features between the unfrozen HSCs and cryopreserved HSCs was performed at each passage using the following techniques: light microscopy, immunohistochemistry, cell growth curve, metallothionein (MTT) assay, and PI staining, Western blot, real-time polymerase chain reaction (PCR), and gene expression analysis using microarrays. The purity of HSCs was more than 90% in all passages. α-Smooth muscle actin (SMA-)positive HSCs gradually increased in successive passages, and the positive cell rate and rate of increase in cell number were similar in both groups. Expression of platelet-derived growth factor (PDGF) receptor, transforming growth factor (TGF)-β receptor, and α-SMA mRNAs and protein was similar during each passage in the two groups. Gene expression was nearly identical at each passage in unfrozen and frozen/thawed samples obtained from the same patient. In conclusion, an adequate protocol for the cryopreservation of human primary cultured HSCs could be established.     

Branched‐Chain Amino Acid–Rich Supplements Containing Microelements Have Antioxidant Effects on Nonalcoholic Steatohepatitis in Mice

Background: The aim of the present study was to elucidate whether the administration of antioxidant‐rich nutrients, including branched‐chain amino acids (BCAAs), microelements, and vitamins, both alone and in combination, has a positive impact on liver function in a nonalcoholic steatohepatitis (NASH) mouse model and identify the mechanisms underlying these effects. Methods: Seven‐week‐old male KKAy mice fed a methionine‐ and choline‐deficient diet (MCD) for 4 weeks were divided into 7 groups and fed the following planned diets for another 4 weeks: group A (normal diet), group B (MCD; control), group C (MCD with rich microelements), group D (MCD with rich BCAAs), group E (MCD with rich microelements and BCAAs), and group F (MCD with rich microelements, BCAAs, and vitamins). We then conducted biochemical assays, histological analyses, immunohistochemistry for 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) and 4‐hydroxy‐2′‐nonenal (4‐HNE), and Western blotting for insulin glucose signaling, lipid metabolism, and endoplasmic reticulum (ER) stress–related signaling in liver specimens obtained from mice in each group. Results: The morphometric grades of all NASH‐related findings and the mean degree of 8‐OHdG immunolocalization in groups D–F were significantly lower than those observed in group B. The expression levels of insulin receptor β subunit (IRβ) and p‐elF in groups E and F and those of phosphatidyl‐inositol 3 kinase (PI3K85), p‐AcelCoA, and PERK in group F were similar to those noted in group A. Conclusions: The administration of a combination of antioxidant‐rich nutrients, including BCAAs and microelements, is likely to suppress the progression of NASH by reducing oxidative stress, primarily via the downregulation of the ER stress pathway.     

Epidermal growth factor receptor inhibitor-related skin toxicity: mechanisms, treatment, and its potential role as a predictive marker

The human epidermal growth factor receptor (HER1/EGFR/ErbB1) signaling is aberrant and overexpressed in many solid malignancies making it an appealing target for biologic agents. Among the classes of drugs targeting EGFR are monoclonal antibodies and EGFR tyrosine kinase inhibitors, which have been shown effective and generally well tolerated in different clinical settings. The majority of patients treated with EGFR inhibitors (EGFRIs) develop specific dose-dependent skin toxicity. This side effect may lead to physical and psychosocial discomfort which can result in dose reduction or treatment interruption. The relationship between rash and clinical outcome has stimulated interest in this particular toxicity as a possible surrogate marker of efficacy in patients treated with targeted agents against EGFR. This review aims to summarize and update the current knowledge of the clinical presentation, predictive and prognostic value, and the management of EGFRI-related skin toxicity.