Posttranslational ruling of xanthine oxidase activity in bovine milk by its substrates

The aims of this study were to test the hypothesis that the substrates of xanthine oxidase (XO), xanthine and hypoxanthine, are consumed while the milk is stored in the gland between milkings, and to explore how XO activity responds to bacteria commonly associated with subclinical infections in the mammary gland. Freshly secreted milk was obtained following complete evacuation of the gland and induction of milk ejection with oxytocin. In bacteria-free fresh milk xanthine and hypoxanthine were converted to uric acid within 30 min (T1/2 approximately 10 min), which in turn provides electrons for formation of hydrogen peroxide and endows the alveolar lumen with passive protection against invading bacteria. On the other hand, the longer residence time of milk in the cistern compartment was not associated with oxidative stress as a result of XO idleness caused by exhaustion of its physiological fuels. The specific response of XO to bacteria species and the resulting bacteria-dependent nitrosative stress further demonstrates that it is part of the gland immune system.     

Extended exposure to Sonic hedgehog is required for patterning the posterior digits of the vertebrate limb

Sonic hedgehog (Shh) is a key signal in establishing different digit fates along the anterior-posterior axis of the vertebrate limb bud. Although the anterior digits appear to be specified by differential concentrations of Shh in a traditional, morphogen-like response, recent studies have suggested that posterior digits are specified by an extended time of exposure to Shh rather than, or in addition to, a threshold concentration of Shh. This model for digit patterning depends upon continued Shh signaling in the posterior limb through mid-to-late bud stages. We find that cyclopamine, a potent antagonist of Shh signaling, can down-regulate hedgehog target genes in the posterior limb throughout the time Shh is expressed, indicating that continued active Shh signaling indeed takes place. To further explore the relative roles of time and concentration of Shh during limb development, we carried out two additional series of experiments. To test the effect of limiting the time, but not the amount of Shh produced, we treated chick embryos with the hedgehog antagonist cyclopamine at various stages of limb development. We find that short exposures to Shh result in specification of only the most anterior digits and that more posterior digits are specified sequentially with increasing times of uninterrupted Shh activity. To test the effect of limiting the level of Shh produced, but not the time of exposure, we genetically modified Shh production in mice. As previously shown, reducing both the concentration of Shh produced and the duration of Shh exposure results in a loss of posterior digits. We find that maintaining a low level of Shh production throughout the normal time frame of ZPA signaling results in a near complete restoration of the posterior-most digits. These data are consistent with, and lend additional support to, the model that concentration of Shh seen and duration of exposure both contribute to the dose-dependent specification of digit identities, but for the posterior-most digits the temporal component is the more critical parameter.     

Characterization of human embryonic stem cell lines by the International Stem Cell Initiative

The International Stem Cell Initiative characterized 59 human embryonic stem cell lines from 17 laboratories worldwide. Despite diverse genotypes and different techniques used for derivation and maintenance, all lines exhibited similar expression patterns for several markers of human embryonic stem cells. They expressed the glycolipid antigens SSEA3 and SSEA4, the keratan sulfate antigens TRA-1-60, TRA-1-81, GCTM2 and GCT343, and the protein antigens CD9, Thy1 (also known as CD90), tissue-nonspecific alkaline phosphatase and class 1 HLA, as well as the strongly developmentally regulated genes NANOG, POU5F1 (formerly known as OCT4), TDGF1, DNMT3B, GABRB3 and GDF3. Nevertheless, the lines were not identical: differences in expression of several lineage markers were evident, and several imprinted genes showed generally similar allele-specific expression patterns, but some gene-dependent variation was observed. Also, some female lines expressed readily detectable levels of XIST whereas others did not. No significant contamination of the lines with mycoplasma, bacteria or cytopathic viruses was detected.     

Molecular profile of ultrastructure changes of the ligamentum flavum related to lumbar spinal canal stenosis

Lumbar spinal canal stenosis (LSCS) is a degenerative disease observed by hypertrophy of the ligamentum flavum (LF) that cause compression of the lumbar neural content. Diabetes mellitus (DM) is a risk factor for the disease and we have shown previously that DM increases the fibrosis and elastic fiber loss in patients with LSCS. The purpose of this study was to find the proteins that play a role in the development of this clinical pathogenesis and the effect of DM on protein expression. LF tissue retrieved from patients diagnosed with LSCS, some were also diagnosed with DM, were compared with LF from patients diagnosed with herniated nucleus pulposus (HNP). The tissues were analyzed by mass spectrometry for proteins profile alteration. We found that LF of LSCS/DM patients exhibited significantly higher levels of proteoglycan proteins and latent transforming growth factor β-binding protein (LTBP2 and LTBP4). Additionally, an increase of HTRA serine protease 1 and insulin-like growth factor binding protein-5 were noted. The higher fibrosis was also associated with proteins related to inflammation and slower tissue repair. Collagen 6 and transforming growth factor inhibitor are related to activation of the anti-inflammatory M2 pathway that is associated with tissue repair. The decrease of these proteins expression in LSCS/DM is associated with increased levels and activation of M1 pro-inflammatory pathways. Interestingly, C3 and C4b members of the complement complex and mannose receptor-like protein (CLEC18) paralogous proteins were detectable solely at the LSCS/DM patients’ samples. Histology analysis shows that inflammatory was induced by the hyperglycemic conditions in diabetic patients involve in altering the matrix compositions. Thus, the protein profiles associated with inflammatory pathways affecting the LF suggested increasing susceptibility of developing the degeneration under hyperglycemic conditions.     

The Molecular and Metabolic Influence of Long Term Agmatine Consumption

Agmatine (AGM), a product of arginine decarboxylation, influences multiple physiologic and metabolic functions. However, the mechanism(s) of action, the impact on whole body gene expression and metabolic pathways, and the potential benefits and risks of long term AGM consumption are still a mystery. Here, we scrutinized the impact of AGM on whole body metabolic profiling and gene expression and assessed a plausible mechanism(s) of AGM action. Studies were performed in rats fed a high fat diet or standard chow. AGM was added to drinking water for 4 or 8 weeks. We used ¹³C or ¹⁵N tracers to assess metabolic reactions and fluxes and real time quantitative PCR to determine gene expression. The results demonstrate that AGM elevated the synthesis and tissue level of cAMP. Subsequently, AGM had a widespread impact on gene expression and metabolic profiling including (a) activation of peroxisomal proliferator-activated receptor-α and its coactivator, PGC1α, and (b) increased expression of peroxisomal proliferator-activated receptor-γ and genes regulating thermogenesis, gluconeogenesis, and carnitine biosynthesis and transport. The changes in gene expression were coupled with improved tissue and systemic levels of carnitine and short chain acylcarnitine, increased β-oxidation but diminished incomplete fatty acid oxidation, decreased fat but increased protein mass, and increased hepatic ureagenesis and gluconeogenesis but decreased glycolysis. These metabolic changes were coupled with reduced weight gain and a curtailment of the hormonal and metabolic derangements associated with high fat diet-induced obesity. The findings suggest that AGM elevated the synthesis and levels of cAMP, thereby mimicking the effects of caloric restriction with respect to metabolic reprogramming.     

Expanding the boundaries of embryonic stem cells

The boundaries of embryonic stem cell (ESC) research have extended considerably in recent years in several?important ways. Alongside a deeper understanding of the pluripotent state, ESCs have been successfully integrated into various fields, such as genomics, epigenetics, and disease modeling. Significant progress in cell fate control has pushed directed differentiation and tissue engineering further than ever before and promoted clinical trials. The geographical distribution of research activity has also expanded, especially for human ESCs. This review outlines these developments and future challenges that remain.     

Multilevel-3D bit patterned magnetic media with 8 signal levels per nanocolumn

This letter presents an experimental study that shows that a 3(rd) physical dimension may be used to further increase information packing density in magnetic storage devices. We demonstrate the feasibility of at least quadrupling the magnetic states of magnetic-based data storage devices by recording and reading information from nanopillars with three magnetically-decoupled layers. Magneto-optical Kerr effect microscopy and magnetic force microscopy analysis show that both continuous (thin film) and patterned triple-stack magnetic media can generate eight magnetically-stable states. This is in comparison to only two states in conventional magnetic recording. Our work further reveals that ferromagnetic interaction between magnetic layers can be reduced by combining Co/Pt and Co/Pd multilayers media. Finally, we are showing for the first time an MFM image of multilevel-3D bit patterned media with 8 discrete signal levels.     

The in vitro survival of human monosomies and trisomies as embryonic stem cells

Chromosomal aneuploidies are responsible for severe human genetic diseases. Aiming at creating models for such disorders, we have generated human embryonic stem cell (hESC) lines from pre-implantation genetic screened (PGS) embryos. The overall analysis of more than 400 aneuploid PGS embryos showed a similar risk of occurrence of monosomy or trisomy for any specific chromosome. However, the generation of hESCs from these embryos revealed a clear bias against monosomies in autosomes. Moreover, only specific trisomies showed a high chance of survival as hESC lines, enabling us to present another categorization of human aneuploidies. Our data suggest that chromosomal haploinsufficiency leads to lethality at very early stages of human development.     

From Causation to Correlation: The Story of Psychosomatic Medicine 1939–1979

This study focuses on the first four decades inthe history of the pioneering journal Psychosomatic Medicine. The goal of thejournal as stated by its founders was to reformmedicine by scientifically reintegrating the``mind' into medicine. However, from itsinception, the editorial members were hauntedby internal ambiguity regarding the nature ofpsychosomatic knowledge. This led to recurrentidentity crises. This study tells the story ofthe complex interplay between internal andexternal forces shaping PsychosomaticMedicine's institutional transitions andepistemological transformations. Itdemonstrates how, despite this continuousinternal confusion, the level of consistencynecessary for gaining legitimacy increasedduring the process of evaluating papers. Theincreased level of standardization coincidedwith a transition in the psychosomaticmovement's epistemological approach: from causation to correlation. The initialattempt to search for causal mechanismslinking the psyche and the soma were replacedby correlational models measuring variousmanifestations of psychological and biologicalphenomena in a way that presupposed andreduplicated the split the founders ironicallysought to supersede.