Regulation of acetylation of plant cell wall components is complex and responds to external stimuli.

Previously, we reported that the allelic de-etiolated by zinc (dez) and trichome birefringence (tbr) mutants exhibit photomorphogenic development in the dark, which is enhanced by high Zn. TRICHOME BIREFRINGENCE-LIKE proteins had been implicated in transferring acetyl groups to various hemicelluloses. Pectin O-acetylation levels were lower in dark-grown dez seedlings than in the wild type. We observed Zn-enhanced photomorphogenesis in the dark also in the reduced wall acetylation 2 (rwa2-3) mutant, which exhibits lowered O-acetylation levels of cell wall macromolecules including pectins and xyloglucans, supporting a role for cell wall macromolecule O-acetylation in the photomorphogenic phenotypes of rwa2-3 and dez. Application of very short oligogalacturonides (vsOGs) restored skotomorphogenesis in dark-grown dez and rwa2-3. Here we demonstrate that in dez, O-acetylation of non-pectin cell wall components, notably of xyloglucan, is enhanced. Our results highlight the complexity of cell wall homeostasis and indicate against an influence of xyloglucan O-acetylation on light-dependent seedling development.

Spray-assisted alignment of Layer-by-Layer assembled silver nanowires: a general approach for the preparation of highly anisotropic nano-composite films.

The present article focuses on the build-up and the properties of oriented silver nanowire monolayer films and Layer-by-Layer assembled multilayer films. We describe the template-free oriented spray-assisted assembly of silver nanowires at solid/air-interfaces using Grazing Incidence Spraying, a simple and versatile approach that allows the formation of highly oriented thin films with a tunable density and in-plane orientation. Depending on the spraying conditions the nematic order parameter, which describes the angular spread of misaligned nanowires, can be as high as 0.98 (a value of 1.00 corresponding to a perfectly parallel alignment). The combination with the Layer-by-Layer assembly allows building multilayer thin films possessing in-plane anisotropy. In order to demonstrate that the local alignment does not cancel out on the macroscopic scale but leads to direction-dependent properties, we use linearly polarized UV-Vis-NIR spectroscopy to probe the selective excitation of the transverse and longitudinal localized plasmon resonances of the nanowires. The polarization efficiency of the thin films increases strongly with the in-plane density, the degree of orientation, and the number of silver nanowire layers. Multilayer films containing 4 layers of nanowires oriented in the same direction reach a polarization efficiency of up to 97% in the near-infrared region.

Anisotropic optical and conductive properties of oriented 1D-nanoparticle thin films made by spray-assisted self-assembly.

We report on the fabrication of oriented anisotropic metal nanoparticle thin films made by Grazing Incidence Spraying (GIS) and on the anisotropic plasmonic properties of the resulting thin films. Gold nanorods of two different aspect ratios and silver nanowires were self-assembled as a uniaxially aligned monolayer with the GIS approach. In particular, we examine the influence of the nanowire/nanorod length and diameter on the degree of ordering determined by electron microscopy pictures. Furthermore, we show that the anisotropy of the optical properties (probed by polarized UV-visible-near infrared spectroscopy) strongly depend on the quality of alignment. The prepared monolayer thin films have an orientation order parameter of up to 0.83 for silver nanowires, which is reflected in an optical anisotropy of 0.57 in the UV-visible and 0.76 in the near infrared through the selective excitation of transverse and longitudinal surface plasmon resonance modes. The electronic transport in oriented silver nanowire monolayers is also shown to be highly directional, with the sheet resistance varying over almost an order of magnitude depending on the transport direction. Such anisotropic conductive plasmonic thin films may find applications in various fields like biochemical sensing, energy transport and harvesting or optoelectronic devices.

Protective effect of myostatin gene deletion on aging-related muscle metabolic decline.

While myostatin gene deletion is a promising therapy to fight muscle loss during aging, this approach induces also skeletal muscle metabolic changes such as mitochondrial deficits, redox alteration and increased fatigability. In the present study, we evaluated the effects of aging on these features in aged wild-type (WT) and mstn knockout (KO) mice. Moreover, to determine whether an enriched-antioxidant diet may be useful to prevent age-related disorders, we orally administered to the two genotypes a melon concentrate rich in superoxide dismutase for 12 weeks. We reported that mitochondrial functional abnormalities persisted (decreased state 3 and 4 of respiration; p<0.05) in skeletal muscle from aged KO mice; however, differences with WT mice were attenuated at old age in line with reduced difference on running endurance between the two genotypes. Interestingly, we showed an increase in glutathione levels, associated with lower lipid peroxidation levels in KO muscle. Enriched antioxidant diet reduced the aging-related negative effects on maximal aerobic velocity and running limit time (p<0.05) in both groups, with systemic adaptations on body weight. The redox status and the hypertrophic phenotype appeared to be beneficial to KO mice, mitigating the effect of aging on the skeletal muscle metabolic remodeling.

Comparison of environmental risk factors for esophageal atresia, anorectal malformations, and the combined phenotype in 263 German families.

Esophageal atresia with or without tracheoesophageal fistula (EA/TEF) and anorectal malformations (ARM) represent the severe ends of the fore- and hindgut malformation spectra. Previous research suggests that environmental factors are implicated in their etiology. These risk factors might indicate the influence of specific etiological mechanisms on distinct developmental processes (e.g. fore- vs. hindgut malformation). The present study compared environmental factors in patients with isolated EA/TEF, isolated ARM, and the combined phenotype during the periconceptional period and the first trimester of pregnancy in order to investigate the hypothesis that fore- and hindgut malformations involve differing environmental factors. Patients with isolated EA/TEF (n = 98), isolated ARM (n = 123), and the combined phenotype (n = 42) were included. Families were recruited within the context of two German multicenter studies of the genetic and environmental causes of EA/TEF (great consortium) and ARM (CURE-Net). Exposures of interest were ascertained using an epidemiological questionnaire. Chi-square, Fisher's exact, and Mann-Whitney U-tests were used to assess differences between the three phenotypes. Newborns with isolated EA/TEF and the combined phenotype had significantly lower birth weights than newborns with isolated ARM (P = 0.001 and P < 0.0001, respectively). Mothers of isolated EA/TEF consumed more alcohol periconceptional (80%) than mothers of isolated ARM or the combined phenotype (each 67%). Parental smoking (P = 0.003) and artificial reproductive techniques (P = 0.03) were associated with isolated ARM. Unexpectedly, maternal periconceptional multivitamin supplementation was most frequent among patients with the most severe form of disorder, i.e. the combined phenotype (19%). Significant differences in birth weight were apparent between the three phenotype groups. This might be attributable to the limited ability of EA/TEF fetuses to swallow amniotic fluid, thus depriving them of its nutritive properties. Furthermore, the present data suggest that fore- and hindgut malformations involve differing environmental factors. Maternal periconceptional multivitamin supplementation was highest among patients with the combined phenotype. This latter finding is contrary to expectation, and warrants further analysis in large prospective epidemiological studies.

An Arabidopsis gene regulatory network for secondary cell wall synthesis.

The plant cell wall is an important factor for determining cell shape, function and response to the environment. Secondary cell walls, such as those found in xylem, are composed of cellulose, hemicelluloses and lignin and account for the bulk of plant biomass. The coordination between transcriptional regulation of synthesis for each polymer is complex and vital to cell function. A regulatory hierarchy of developmental switches has been proposed, although the full complement of regulators remains unknown. Here we present a protein-DNA network between Arabidopsis thaliana transcription factors and secondary cell wall metabolic genes with gene expression regulated by a series of feed-forward loops. This model allowed us to develop and validate new hypotheses about secondary wall gene regulation under abiotic stress. Distinct stresses are able to perturb targeted genes to potentially promote functional adaptation. These interactions will serve as a foundation for understanding the regulation of a complex, integral plant component.

Prevention and treatment of Clostridium perfringens epsilon toxin intoxication in mice with a neutralizing monoclonal antibody (c4D7) produced in Nicotiana benthamiana.

Epsilon toxin (ETX), produced by Clostridium perfringens types B and D, is among the most lethal toxins known. ETX is a potential bioterrorism threat that was listed as a Category B agent by the U.S. Centers for Disease Control until 2012 and it still remains a toxin of interest for several government agencies. We produced a monoclonal antibody (MAb) against ETX (ETX MAb c4D7) in Nicotiana benthamiana and characterized its preventive and therapeutic efficacy in mice. The ETX preparation used was highly lethal for mice (LD50 = 1.6 µg/kg) and resulted in a mean time from inoculation to death of 18 and 180 min when administered intravenously or intraperitoneally, respectively. High lethal challenge resulted in dramatic increases of a variety of pro-inflammatory cytokines in serum, while lower, but still lethal doses, did not elicit such responses. ETX MAb c4D7 was highly effective prophylactically (ED50 = 0.3 mg/kg; ED100 = 0.8 mg/kg) and also provided protection when delivered 15-30 min post-ETX intoxication. These data suggest that ETX MAb c4D7 may have use as a pre- and post-exposure treatment for ETX intoxication.

Telaprevir or boceprevir triple therapy in patients with chronic hepatitis C and varying severity of cirrhosis.

BACKGROUND: Risks and benefits of protease inhibitor (PI) (telaprevir or boceprevir) triple therapy in hepatitis C virus (HCV)-infected patients with mildly decompensated cirrhosis, including those wait-listed for liver transplantation (LT), are incompletely known. AIM: To assess virological responses and safety of PI triple therapy in patients with mildly decompensated Child-Pugh (CP) CP ≥6 vs. compensated (CP = 5) cirrhosis. METHODS: Multicentre cohort of 160 adults with cirrhosis treated with peginterferon/ribavirin (peg-IFN/RBV) plus telaprevir (69%) or boceprevir (31%), comparing outcomes between those with CP = 5 and CP ≥6. RESULTS: Patients, 47% with CP ≥6 cirrhosis (CP range 6-10), received PI triple therapy for a targeted duration of 48 weeks. The cohort was median age 59 years, 32% female, 59% genotype 1a, 35% previous null/partial responders. Sustained virological response at 12 weeks (SVR12) was achieved by 35% of patients with CP ≥6 vs. 54% of those with CP = 5 (P = 0.02). CP = 5, achievement of rapid virological response and genotype 1b/other, independently predicted SVR12. Compared to those with CP = 5, patients with CP ≥6 had more peg-IFN dose reductions, eltrombopag use, transfusions and hospitalisations to manage adverse events (all P < 0.05). Overall, 67 (42%) discontinued treatment early. Nine wait-listed patients were treated for a median of 97 days (IQR 60-160) prior to liver transplantation and five achieved post-LT SVR. CONCLUSIONS: In the presence of mild decompensation (Child-Pugh ≥6), SVR12 rates with protease inhibitor triple therapy are significantly reduced and adverse events increased. Thus, treatment with protease inhibitor triple therapy, if judged as necessary, should be undertaken with close monitoring and awareness of the significant risks.

A hydrodynamically optimized nano-electrospray ionization source and vacuum interface.

The coupling of atmospheric pressure ionization (API) sources like electrospray ionization (ESI) to vacuum based applications like mass spectrometry (MS) or ion beam deposition (IBD) is done by differential pumping, starting with a capillary or pinhole inlet. Because of its low ion transfer efficiency the inlet represents a major bottleneck for these applications. Here we present a nano-ESI vacuum interface optimized to exploit the hydrodynamic drag of the background gas for collimation and the reduction of space charge repulsion. Up to a space charge limit of 40 nA we observe 100% current transmission through a capillary with an inlet and show by MS and IBD experiments that the transmitted ion beams are well defined and free of additional contamination compared to a conventional interface. Based on computational fluid dynamics modelling and ion transport simulations, we show how the specific shape enhances the collimation of the ion cloud. Mass selected ion currents in the nanoampere range available further downstream in high vacuum open many perspectives for the efficient use of electrospray ion beam deposition (ES-IBD) as a surface coating method.

Nanotrench for nano and microparticle electrical interconnects.

We present a simple and versatile patterning procedure for the reliable and reproducible fabrication of high aspect ratio (10(4)) electrical interconnects that have separation distances down to 20 nm and lengths of several hundreds of microns. The process uses standard optical lithography techniques and allows parallel processing of many junctions, making it easily scalable and industrially relevant. We demonstrate the suitability of these nanotrenches as electrical interconnects for addressing micro and nanoparticles by realizing several circuits with integrated species. Furthermore, low impedance metal-metal low contacts are shown to be obtained when trapping a single metal-coated microsphere in the gap, emphasizing the intrinsic good electrical conductivity of the interconnects, even though a wet process is used. Highly resistive magnetite-based nanoparticles networks also demonstrate the advantage of the high aspect ratio of the nanotrenches for providing access to electrical properties of highly resistive materials, with leakage current levels below 1 pA.

Pseudomembranous colitis without diarrhea presenting clinically as acute intestinal pseudo-obstruction.

Pseudomembranous colitis usually presents with diarrhea in a clinical setting of recent antibiotic use. It is uncommon to see it as a cause of obstipation and colonic pseudo-obstruction. We report an unusual case of an elderly woman with hypertension, congestive heart failure, chronic obstructive pulmonary disease, chronic renal insufficiency, and diabetes mellitus, who was admitted with fever, abdominal pain, and distension without diarrhea. She presented with decreased stool frequency and obstipation. She did not respond to conservative management. Colonoscopy revealed a picture of pseudomembranous colitis, and Clostridium difficile toxin was positive. She responded well to metronidazole therapy.

HMO behavior and stock market valuation: what does Wall Street reward and punish?

This article analyzes the variation in returns to owning stock in investor-owned health maintenance organizations (IOHMOs) for the period 1994-1997. The average return (measured by the change in the market value of the stock plus dividends) was close to zero, but returns were positive and high for firms operating in local markets that were and remained less competitive, with large nationwide scope, and with less rapidly growing panels of contracted physicians. Indicators of a firm's strategic direction were abstracted from their annual reports; firms pursuing a merger or acquisition strategy, and those emphasizing a utilization review strategy, showed lower returns than those that did not. Other strategy and market variables were not related to stock market returns over this period, and were also generally not related to price-earnings ratios. This analysis supports the view that competitive HMO markets best constrain profits to investor-owned firms.

Effect of meta-tetra(hydroxyphenyl)chlorin (mTHPC)-mediated photodynamic therapy on sensitive and multidrug-resistant human breast cancer cells.

Meta-tetra(hydroxyphenyl)chlorin (mTHPC) is in clinical trials for the photodynamic therapy (PDT) of localized-stage cancer. The PDT susceptibility of cells expressing multidrug resistance (MDR) phenotype is an attractive possibility to overcome the resistance to cytotoxic drugs observed during cancer chemotherapy. The accumulation, photocytotoxicity and intracellular localization of mTHPC were examined using the doxorubicin selected MCF-7/DXR human breast cancer cells, expressing P-glycoprotein (P-gp), and the wild-type parental cell line, MCF-7. No significant difference in mTHPC accumulation was observed between the two cell lines up to 3 h contact. The photodynamic activity of mTHPC, measured 24 h after irradiation with red laser light (lambda=650 nm), was significantly greater in MCF-7/DXR as compared to MCF-7 cells. A light dose of 2.5 J cm(-2) inducing 50% of cytotoxicity in MCF-7, resulted in 85% cytotoxicity in MCF-7/DXR. The presence of P-gp inhibitors SDZ-PSC-833 and cyclosporin A did not modify the mTHPC-induced cytotoxicity. The difference in intracellular mTHPC distribution pattern between two cell lines may contribute to different photocytotoxicity. Our results indicate that mTHPC mediated PDT could be useful in killing cells expressing MDR phenotype.

Kirsten ras mutations in patients with colorectal cancer: the 'RASCAL II' study.

Researchers worldwide with information about the Kirsten ras (Ki-ras) tumour genotype and outcome of patients with colorectal cancer were invited to provide that data in a schematized format for inclusion in a collaborative database called RASCAL (The Kirsten ras in-colorectal-cancer collaborative group). Our results from 2721 such patients have been presented previously and for the first time in any common cancer, showed conclusively that different gene mutations have different impacts on outcome, even when the mutations occur at the same site on the genome. To explore the effect of Ki-ras mutations at different stages of colorectal cancer, more patients were recruited to the database, which was reanalysed when information on 4268 patients from 42 centres in 21 countries had been entered. After predetermined exclusion criteria were applied, data on 3439 patients were entered into a multivariate analysis. This found that of the 12 possible mutations on codons 12 and 13 of Kirsten ras, only one mutation on codon 12, glycine to valine, found in 8.6% of all patients, had a statistically significant impact on failure-free survival (P = 0.004, HR 1.3) and overall survival (P = 0.008, HR 1.29). This mutation appeared to have a greater impact on outcome in Dukes' C cancers (failure-free survival, P = 0.008, HR 1.5; overall survival P = 0.02, HR 1.45) than in Dukes' B tumours (failure-free survival, P = 0.46, HR 1.12; overall survival P = 0.36, HR 1.15). Ki-ras mutations may occur early in the development of pre-cancerous adenomas in the colon and rectum. However, this collaborative study suggests that not only is the presence of a codon 12 glycine to valine mutation important for cancer progression but also that it may predispose to more aggressive biological behaviour in patients with advanced colorectal cancer.

Insurance and new technology: from hospital to drugstore.

This paper traces the relationship between insurance coverage and the technology-induced shift of the locus of medical care and medical spending from the inpatient to the outpatient setting. This shift was accompanied by an increase in the extent of private insurance coverage for outpatient treatments; technological change both caused the increase in coverage (for more costly treatments) and was affected by it (as lower user prices increased the demand for new types of care). Changes in insurance administration technology also facilitated the transformation. Some aspects of the change may have been inefficient, because of the presence of tax subsidy and legal requirements to cover costly new technologies of low effectiveness, but the transformation appears thus far to have worked better for private insurance than for Medicare.

Functional cloning of an endo-arabinanase from Aspergillus aculeatus and its heterologous expression in A. or oryzae and tobacco.

Functional cloning in yeast has been used to isolate full-length cDNAs encoding an endo-alpha-1,5-L-arabinanase from the filamentous fungus Aspergillus aculeatus. Screening of a cDNA library constructed in a yeast expression vector for transformants that hydrolysed AZCL-arabinan identified 44 Saccharomyces cerevisiae clones all harbouring the same arabinanase-encoding cDNA. The cloned cDNA was expressed in A. oryzae and the recombinant enzyme was purified and characterized. The mode of action of the enzyme was studied by analysis of the digestion pattern towards debranched arabinan. The digestion profile obtained strongly suggests that the enzyme is an endo-arabinanase. In addition, the feasibility using Nicotiana tabacum as an alternative host for arabinanase expression was investigated.

Changes in the structure of xyloglucan during cell elongation.

Xyloglucans were isolated by sequential extraction of the cell walls of pea (Pisum sativum L. cv. Alaska) with a xyloglucan-specific endoglucanase and KOH. The xyloglucan content and xyloglucan-oligosaccharide composition were determined for fractions obtained from the elongating and non-elongating segments of pea stems grown in the light and in darkness. The results were consistent with the hypothesis that regulated growth of the cell wall depends on xyloglucan metabolism. Furthermore, the characterization of xyloglucan extracted from leaves of light-grown pea plants indicates that xyloglucan metabolism is tissue specific. Changes in xyloglucan subunit structure observed in elongating stems are consistent with the in muro realization of a metabolic pathway that was previously proposed solely on the basis of the in vitro activities of plant glycosyl hydrolases.

Alternative valuations of work loss and productivity.

In this article, we examine the indirect costs (i.e., work loss and productivity costs) of employee illness from the employer's perspective. We provide a conceptual framework to help employers consider alternative views with regard to assessing indirect costs and valuing the health care they purchase. First, we discuss the matter of perspective and how an employer should view and assess indirect costs. We briefly review current models of measuring indirect costs, and we critique these models. Then we introduce a simple, conceptual framework based on the ideas of health capital and labor productivity, and we lay out the effects of health investment on indirect costs while considering what employees desire and employers can provide. Finally, we offer an agenda for further research.