Thrombomodulin Contributes to Gamma Tocotrienol-Mediated Lethality Protection and Hematopoietic Cell Recovery in Irradiated Mice

Systemic administration of recombinant thrombomodulin (TM) confers radiation protection partly by accelerating hematopoietic recovery. The uniquely potent radioprotector gamma tocotrienol (GT3), in addition to being a strong antioxidant, inhibits the enzyme hydroxy-methyl-glutaryl-coenzyme A reductase (HMGCR) and thereby likely modulates the expression of TM. We hypothesized that the mechanism underlying the exceptional radioprotective properties of GT3 partly depends on the presence of endothelial TM. In vitro studies confirmed that ionizing radiation suppresses endothelial TM (about 40% at 4 hr after 5 Gy γ-irradiation) and that GT3 induces TM expression (about 2 fold at the mRNA level after 5 μM GT3 treatment for 4 hr). In vivo survival studies showed that GT3 was significantly more effective as a radioprotector in TM wild type (TM^+/+) mice than in mice with low TM function (TM^Pro/-). After exposure to 9 Gy TBI, GT3 pre-treatment conferred 85% survival in TM^+/+ mice compared to only 50% in TM^Pro/-. Thus, GT3-mediated radiation lethality protection is partly dependent on endothelial TM. Significant post-TBI recovery of hematopoietic cells, particularly leukocytes, was observed in TM^+/+ mice (p = 0.003), but not in TM^Pro/- mice, despite the fact that GT3 induced higher levels of granulocyte colony stimulating factor (G-CSF) in TM^Pro/- mice (p = 0.0001). These data demonstrate a critical, G-CSF-independent, role for endothelial TM in GT3-mediated lethality protection and hematopoietic recovery after exposure to TBI and may point to new strategies to enhance the efficacy of current medical countermeasures in radiological/nuclear emergencies.     

Duration of Cord Clamping and Neonatal Outcomes in Very Preterm Infants

Background

Delayed cord clamping (DCC, ≥30s) increases blood volume in newborns and is associated with fewer blood transfusions and short-term neonatal complications. The optimal timing of cord clamping for very preterm infants should maximize placental transfusion without interfering with stabilization and resuscitation.

Aim

We compared the effect of different durations of DCC, 30-45s vs. 60-75s, on delivery room (DR) and neonatal outcomes in preterm infants <32 weeks gestational age (GA).

Methods

This is a single-center prospective observational study. Data were collected prospectively from eligible infants from two groups: 30-45s DCC group (January 2008 to February 2011, n = 187) and 60-75s DCC group (March 2011 to April 2014, n = 166).

Results

The 60-75s DCC group compared to the 30-45s DCC group had higher hematocrits at <2 hours (49.2% vs. 47.4%, p = 0.02). In infants <28 weeks GA, the 12–36 hours hematocrit was higher in the 60-75s DCC group compared to the 30-45s DCC group (47.9% vs. 42.1%, p = 0.002). The 60-75s DCC group had reductions in DR intubation (11% vs. 22%, p = 0.004), hypothermia on admission (1% vs. 5%, p = 0.01), surfactant therapy (13% vs. 28%, p = 0.001), intubation in the first 24 hours (20% vs. 34%, p = 0.004), any intubation (27% vs. 40%, p = 0.007), and any red blood cell transfusion (20% vs. 33%, p = 0.008) during the hospitalization compared to the 30-45s DCC group. These reductions remained significant after adjusting for GA, gender and >48 hours of antenatal steroid exposure. There was no difference between the two groups in neonatal death, intraventricular hemorrhage, chronic lung disease, late onset sepsis, necrotizing enterocolitis and severe retinopathy of prematurity.

Conclusion

In this study cohort increasing DCC duration from 30-45s to 60-75s is associated with decreased hypothermia on admission, neonatal respiratory interventions and red blood cell transfusions without increase in neonatal mortality and morbidities.     

Curcumin Conjugated with PLGA Potentiates Sustainability,Anti-Proliferative Activity and Apoptosis in Human Colon Carcinoma Cells

Curcumin, an ingredient of turmeric, exhibits a variety of biological activities such as anti-inflammatory, anti-atherosclerotic, anti-proliferative, anti-oxidant, anti-cancer and anti-metastatic. It is a highly pleiotropic molecule that inhibits cell proliferation and induces apoptosis in cancer cells. Despite its imperative biological activities, chemical instability, photo-instability and poor bioavailability limits its utilization as an effective therapeutic agent. Therefore, enhancing the bioavailability of curcumin may improve its therapeutic index for clinical setting. In the present study, we have conjugated curcumin with a biodegradable polymer Poly (D, L-lactic-co-glycolic acid) and evaluated its apoptotic potential in human colon carcinoma cells (HCT 116). The results show that curcumin-PLGA conjugate efficiently inhibits cell proliferation and cell survival in human colon carcinoma cells as compared to native curcumin. Additionally, curcumin conjugated with PLGA shows improved cellular uptake and exhibits controlled release at physiological pH as compared to native curcumin. The curcumin-PLGA conjugate efficiently activates the cascade of caspases and promotes intrinsic apoptotic signaling. Thus, the results suggest that conjugation potentiates the sustainability, anti-proliferative and apoptotic activity of curcumin. This approach could be a promising strategy to improve the therapeutic index of cancer therapy.     

Easily recyclable chiral polymeric Mn(III) salen complexes for oxidative kinetic resolution of racemic secondary alcohols

Chiral polymeric Mn(III) salen complexes were used efficiently for oxidative kinetic resolution of racemic secondary alcohols at room temperature. High chiral purity (ee; >99%) was achieved for the oxidative kinetic resolution of racemic secondary alcohols with 0.6 mol % catalyst loading in 60 min. The catalyst was easily recycled for five successive catalytic experiments.     

Patterning the zebrafish diencephalon by the conserved zinc-finger protein Fezl

The forebrain constitutes the most anterior part of the central nervous system, and is functionally crucial and structurally conserved in all vertebrates. It includes the dorsally positioned telencephalon and eyes, the ventrally positioned hypothalamus, and the more caudally located diencephalon [from rostral to caudal: the prethalamus, the zona limitans intrathalamica (ZLI), the thalamus and the pretectum]. Although antagonizing Wnt proteins are known to establish the identity of the telencephalon and eyes, it is unclear how various subdivisions are established within the diencephalon--a complex integration center and relay station of the vertebrate brain. The conserved forebrain-specific zinc-finger-containing protein Fezl plays a crucial role in regulating neuronal differentiation in the vertebrate forebrain. Here, we report a new and essential role of zebrafish Fezl in establishing regional subdivisions within the diencephalon. First, reduced activity of fezl results in a deficit of the prethalamus and a corresponding expansion of the ZLI. Second, Gal4-UAS-mediated fezl overexpression in late gastrula is capable of expanding the prethalamus telencephalon and hypothalamus at the expense of the ZLI and other fore- and/or mid-brain regions. Such altered brain regionalization is preceded by the early downregulation of wnt expression in the prospective diencephalon. Finally, fezl overexpression is able to restore the anterior forebrain and downregulate wnt expression in Headless- and/or Tcf3 (also known as Tcf7l1a)-deficient embryos. Our findings reveal that Fezl is crucial for establishing regional subdivisions within the diencephalon and may also play a role in the development of the telencephalon and hypothalamus.     

Using reverse micelles as microreactor for hydrogen production by coupled systems of Nostoc / R. palustris and Anabaena / R. palustris

Uptake hydrogenase negative mutants of bloom forming cyanobacteria (Nostoc and Anabaena) and the fermentative bacteria Rhodopseudomonas palustris P₄ were used together for producing hydrogen within the reverse micelles fabricated by N-ethyl hexyl sodium sulfosuccinate (AOT) in isooctane and cetyl trimethyl ammonium bromide (CTAB) in benzene. The rate of H₂ production in AOT/isooctane reverse micellar system was found to be more promising in comparison to the CTAB/Benzene reverse micellar entrapment. After mutagenesis in 2.0% (v/v) ethyl methane sulphonate (EMS) mutants of Nostoc and Anabaena were selected on BG-11 plates (containing 2% agar) and then used for analysis of produced hydrogen. In comparison to the unmutated Nostoc with R. palustris (within AOT/isooctane) the coupled system of mutated Nostoc and R. palustris produced H₂ by 3.9-fold higher rate, which is 8.6 mmol H₂/h/mg protein. Whereas, mutated Anabaena coupled with R. palustris produced 4.8 times higher hydrogen production within (AOT)/isooctane reverse micelles in comparison to the unmutated Anabaena with R. palustris. Effect of nitrogen to carbon ratio (N/C) on hydrogen production was studied and Anabaena/R. palustris and Nostoc/R. palustris systems were, respectively, found to generate 11.2 and 9.8 mmol H₂/h/mg protein continuously for 3 days. Effects of temperature and light intensity were also investigated and we found that 32°C temperature and 1,000 Lux light intensity are the optimum values in these systems. Addition of sodium dithionite also resulted in further enhancement of the rate and duration of hydrogen production in both (mutated Nostoc/R. palustris and mutated Anabaena/R.␣palustris) systems.     

Disaccharide analogs as probes for glycosyltransferases in Mycobacterium tuberculosis

Glycosyltransferases (GTs) play a crucial role in mycobacterial cell wall biosynthesis and are necessary for the survival of mycobacteria. Hence, these enzymes are potential new drug targets for the treatment of tuberculosis (TB), especially multiple drug-resistant TB (MDR-TB). Herein, we report the efficient syntheses of Araf(alpha 1-->5)Araf, Galf(beta 1-->5)Galf, and Galf(beta 1-->6)Galf disaccharides possessing a 5-N,N-dimethylaminonaphthalene-1-sulfonamidoethyl (dansyl) unit that were prepared as fluorescent disaccharide acceptors for arabinosyl- and galactosyl-transferases, respectively. Such analogs may offer advantages relative to radiolabeled acceptors or donors for studying the enzymes and for assay development and compound screening. Additionally, analogs possessing a 5-azidonaphthalene-1-sulfonamidoethyl unit were prepared as photoaffinity probes for their potential utility in studying active site labeling of the GTs (arabinosyl and galactosyl) in Mycobacterium tuberculosis (MTB). Beyond their preparation, initial biological testing and kinetic analysis of these disaccharides as acceptors toward glycosyltransferases are also presented.     

Molecular-functional imaging of cancer: to image and imagine

The integration of advances in molecular biology, synthetic chemistry and visualization techniques has catapulted imaging into a molecular-functional realm, so that imaging is finding basic-research, preclinical and translational applications in cancer. Currently, molecular-imaging capabilities include the ability to image gene expression, receptors, signaling pathways, apoptosis, multidrug resistance and the extracellular matrix (ECM). Functional-imaging capabilities include the ability to assess angiogenesis, hypoxia and metabolism. Traditionally, imaging has played an important role in cancer diagnosing and determining response to treatment. However, it is the realization of the goal of noninvasively visualizing molecules and molecular pathways and relating these to function that makes multi-modality imaging such an exciting and powerful means for studying a multifaceted disease such as cancer.     

Schistosomiasis and pregnancy

Currently, schistosomes infect approximately 40 million women of child-bearing age, yet little is known about schistosome-associated morbidity in pregnant women and their offspring. Animal models indicate a deleterious effect of schistosome infection on maternal, fetal and neonatal outcomes. Case reports have documented maternal infection in association with poor birth outcomes, and two observational studies indicate that maternal schistosome infection might be associated with decreased birth weight. Rigorously identifying and quantifying the impact of schistosome infection on pregnancy outcomes with well-designed observational and treatment studies are crucial for improving birth outcomes in schistosome-endemic areas. In addition, studies that address the safety of praziquantel during pregnancy could lead to further adoption of the recent informal recommendation by the World Health Organization to treat schistosome-infected pregnant and lactating women.