Improved Limits on the Coupling of Ultralight Bosonic Dark Matter to Photons from Optical Atomic Clock Comparisons.

We present improved constraints on the coupling of ultralight bosonic dark matter to photons based on long-term measurements of two optical frequency ratios. In these optical clock comparisons, we relate the frequency of the ^{2}S_{1/2}(F=0)↔^{2}F_{7/2}(F=3) electric-octupole (E3) transition in ^{171}Yb^{+} to that of the ^{2}S_{1/2}(F=0)↔^{2}D_{3/2}(F=2) electric-quadrupole (E2) transition of the same ion, and to that of the ^{1}S_{0}↔^{3}P_{0} transition in ^{87}Sr. Measurements of the first frequency ratio ν_{E3}/ν_{E2} are performed via interleaved interrogation of both transitions in a single ion. The comparison of the single-ion clock based on the E3 transition with a strontium optical lattice clock yields the second frequency ratio ν_{E3}/ν_{Sr}. By constraining oscillations of the fine-structure constant α with these measurement results, we improve existing bounds on the scalar coupling d_{e} of ultralight dark matter to photons for dark matter masses in the range of about (10^{-24}-10^{-17}) eV/c^{2}. These results constitute an improvement by more than an order of magnitude over previous investigations for most of this range. We also use the repeated measurements of ν_{E3}/ν_{E2} to improve existing limits on a linear temporal drift of α and its coupling to gravity.

Seasat low-rate data system.

The Seasat low-rate data system is a distributed, nonreal-time, magnetic-tape system for information processing. Its function is to apply the necessary calibrations, corrections, and conversions to yield geophysically meaningful products from raw spacecraft telemetry data. It also provides a remotely accessible catalog of satellite data.

Toxoplasma and reaction time: role of toxoplasmosis in the origin, preservation and geographical distribution of Rh blood group polymorphism.

The RhD protein which is the RHD gene product and a major component of the Rh blood group system carries the strongest blood group immunogen, the D-antigen. This antigen is absent in a significant minority of the human population (RhD-negatives) due to RHD deletion or alternation. The origin and persistence of this RhD polymorphism is an old evolutionary enigma. Before the advent of modern medicine, the carriers of the rarer allele (e.g. RhD-negative women in the population of RhD-positives or RhD-positive men in the population of RhD-negatives) were at a disadvantage as some of their children (RhD-positive children born to pre-immunized RhD-negative mothers) were at a higher risk of foetal or newborn death or health impairment from haemolytic disease. Therefore, the RhD-polymorphism should be unstable, unless the disadvantage of carriers of the locally less abundant allele is counterbalanced by, for example, higher viability of the heterozygotes. Here we demonstrated for the first time that among Toxoplasma-free subjects the RhD-negative men had faster reaction times than Rh-positive subjects and showed that heterozygous men with both the RhD plus and RhD minus alleles were protected against prolongation of reaction times caused by infection with the common protozoan parasite Toxoplasma gondii. Our results suggest that the balancing selection favouring heterozygotes could explain the origin and stability of the RhD polymorphism. Moreover, an unequal prevalence of toxoplasmosis in different countries could explain pronounced differences in frequencies of RhD-negative phenotype in geographically distinct populations.

Acute and long-term proteome changes induced by oxidative stress in the developing brain.

The developing mammalian brain experiences a period of rapid growth during which various otherwise innocuous environmental factors cause widespread apoptotic neuronal death. To gain insight into developmental events influenced by a premature exposure to high oxygen levels and identify proteins engaged in neurodegenerative and reparative processes, we analyzed mouse brain proteome changes at P7, P14 and P35 caused by an exposure to hyperoxia at P6. Changes detected in the brain proteome suggested that hyperoxia leads to oxidative stress and apoptotic neuronal death. These changes were consistent with results of histological and biochemical evaluation of the brains, which revealed widespread apoptotic neuronal death and increased levels of protein carbonyls. Furthermore, we detected changes in proteins involved in synaptic function, cell proliferation and formation of neuronal connections, suggesting interference of oxidative stress with these developmental events. These effects are age-dependent, as they did not occur in mice subjected to hyperoxia in adolescence.

Epigenetic inheritance in the mouse.

Acquired epigenetic modifications, such as DNA methylation or stable chromatin structures, are not normally thought to be inherited through the germline to future generations in mammals [1] [2]. Studies in the mouse have shown that specific manipulations of early embryos, such as nuclear transplantation, can result in altered patterns of gene expression and induce phenotypic alterations at later stages of development [3] [4] [5]. These effects are consistent with acquired epigenetic modifications that are somatically heritable, such as DNA methylation. Repression and DNA methylation of genes encoding major urinary proteins, repression of the gene encoding olfactory marker protein, and reduced body weight can be experimentally induced by nuclear transplantation in early embryos [4]. Strikingly, we now report that these acquired phenotypes are transmitted to most of the offspring of manipulated parent mice. This is the first demonstration of epigenetic inheritance of specific alterations of gene expression through the germline. These observations establish a mammalian model for transgenerational effects that are important for humal health, and also raise the question of the evolutionary importance of epigenetic inheritance.

Purification of prostaglandin D synthase by ceramic- and size exclusion chromatography.

Prostaglandin D synthase (L-PGDS) is a major glycosylated polypeptide in cerebrospinal fluid (CSF). The overexpression of L-PGDS in inflamed bovine mammary glands indicates its role as biomarker. No diagnostic tool for the quantitative detection of L-PGDS in cows has been reported. Immunometric ELISA tests might help to identify inflamed bovine tissue. The isolation of pure bovine L-PGDS, which is required for the generation of monoclonal antibodies, is an important prerequisite for a diagnostic ELISA test. Our goal was to identify a suitable technique to generate pure L-PGDS from bovine substrates. In the present study a two-step method for the purification of bovine CSF using ceramic hydroxyapatite chromatography followed by size exclusion chromatography is described. Subsequently, the identification of bovine L-PGDS was demonstrated by Western blot analysis and the high grade of the pure product was shown by 2-D PAGE. The yield of purified L-PGDS was 6.8 mg/l bovine CSF. L-PGDS from bovine CSF is shown to consist of multiple isoforms identical in molecular mass and pI values to those in previously described secretions of inflamed bovine mammary glands. In addition, the method was successfully applied to the purification of L-PGDS from human CSF.

[In vitro investigations of phase I metabolism of the fomocaine derivative Oe 9000 with pig liver homogenates]. / In-vitro-Untersuchungen zum Phase-1-Metabolismus des Fomocain-Derivats Oe 9000 mit Schweineleberhomogenaten.

2,2'-[4-(4-Phenoxymethylphenyl)butylimino]diethanol (Oe 9000) is a new, highly potent local anaesthetic related to fomocaine. It displays a long duration of action, low toxicity and is superior to fomocaine with regard to aqueous solubility and efficacy. In view of the development of new application forms, e.g. for the treatment of postoperative pain, the elucidation of the biotransformation of the drug is required. Therefore, experiments with 10000 x g supernatants and microsomes from pig liver homogenates were conducted. Using specifically synthesized reference compounds six phase I metabolites could be identified by LC-MS. Apart from the predominating oxidative desamination of the compound, that led after redox reactions to the corresponding butyric acid and butanol derivatives, oxygenation of the exocycle, oxidative N-desalkylation, and N-oxidation were observed. Thus, with the exception of one compound only metabolites are generated, that are expected to have no local anaesthetic activity due to their reduced basicity.

[Vascular resection and reconstruction techniques in pancreatic surgery]. / Gefäßresektionen und -rekonstruktionen in der Pankreaschirurgie.

BACKGROUND: Vascular resection interventions and the associated necessity of a reconstruction for maintenance particularly of hepatic and small intestinal perfusion are important aspects especially for the surgical treatment of pancreatic cancer. An R0 resection is the only curative treatment option for patients with pancreatic cancer. Venous or arterial vascular infiltration by the tumor and the associated resection and reconstruction for complete tumor removal and establishment of a sufficient perfusion of the dependent organs represents one of the greatest challenges in pancreatic surgery. In addition the oncological significance with respect to arterial vascular resections is controversial. OBJECTIVE: In this review article the indications and technical aspects of vascular resection and reconstruction in the therapy of pancreatic cancer are presented and discussed based on the current literature. MATERIAL AND METHODS: A systematic search of Medline, Embase and the Cochrane Library was carried out to identify studies reporting the results of venous or arterial vascular resection techniques, postoperative morbidity, mortality and patient survival after surgery for pancreatic cancer. Results Pancreatic cancer with vascular infiltration should not principally be seen as non-resectable but must always be checked for the possibility of a curative resection. A decisive factor is the differentiation between venous and arterial vascular involvement. Various safe technical options are available for venous vascular resection, depending on the extent of tumor infiltration. Arterial vascular resections are associated with an increased morbidity and mortality. In selected patients a complete tumor resection and prolonged survival can be achieved by arterial vascular resection.

Isoelectric focusing and electrophoresis combined as a method for defining new point mutations in the mouse.

Isoelectric focusing followed by electrophoresis is a method that allows the survey of the expression of an enormous number of genes in one organism when this method is used for separation of complex protein solutions from the tissue of the organism (protein-mapping method). This makes it possible to use this method for developing a test system aiming at the detection of newly induced or spontaneous point mutations in mammals. A large number of loci could be tested on a relatively small number of individuals. The protein-mapping method was used for the separation of mouse tissue extracts containing soluble proteins or total cell proteins. Several modifications of the method are described. The applicability of this method for defining genetic differences of proteins was demonstrated by an investigation of different strains of mice. Thereafter, a mutagenicity test was initiated with the protein-mapping method. Mice were treated with methyl-nitroso-urea as a potential mutagenic substance and the fetuses of the F1 generation were investigated. Preliminary results suggest that new point mutations were detected with this method.

Analysis of parent-specific gene expression in early mouse embryos and embryonic stem cells using high-resolution two-dimensional electrophoresis of proteins.

Genomic imprinting is an important genetic mechanism in mammals whereby certain genes are epigenetically modified and their expression altered according to their parental origin. The most important consequence of this is the requirement for both a maternal and a paternal genome for normal development to proceed to term. Although there are many instances of specific phenotypes (in the mouse) and diseases (in humans) resulting from imbalances in the parental chromosomes, it is only in the past few years that some of the imprinted genes responsible have been identified. It is however unclear what proportion of the genome is imprinted, particularly in the early embryo. To address the question to what extent parent-specific gene expression occurs in the early embryo and with a possible view to identifying new imprinted genes, the protein profiles of parthenogenetic and normal blastocysts were compared using the technique of high-resolution two-dimensional electrophoresis. The protein profiles of parthenogenetic, androgenetic and normal embryonic stem cells were also compared. Hence parent-specific gene expression was examined in embryonic and extraembryonic lineages of the early embryo. Approximately 1000 polypeptides were examined in each of the analyses, however no parent-specific differences were observed for any of these polypeptides. From this result, it is concluded that expression of genes encoding these polypeptides is identical from the parental chromosomes. These findings have important implications for estimates of the number of imprinted genes in the genome and for the interpretation of phenotypes of parthenogenetic and androgenetic embryos.

Surgery in oesophago-gastric cancer with metastatic disease: Treatment, prognosis and preoperative patient selection.

BACKGROUND: The role of surgical resection in metastatic oesophago-gastric adenocarcinomas (EGA) is not defined and regularly discussed in interdisciplinary tumour boards. Primary objective of this retrospective study was the outcome of patients after surgery. We additionally evaluated our preoperative prognostic score (PPS) based on tumour grading, clinical response to chemotherapy and presumed R-status. METHODS: 123 of 811 EGA patients were evaluated as cM1, either confirmed intraoperatively or by imaging. Response evaluation after chemotherapy was performed by endoscopy, CT-scan and histopathologically. The prospectively documented patient and outcome data were analysed retrospectively. RESULTS: 70 patients with adenocarcinoma of the oesophago-gastric junction and 53 patients with gastric cancer were included. The majority had one M1 site (n = 102). 72 received preoperative chemotherapy (CTx) and 51 underwent primary resection. 11 were explored without resection. 49/112 (40%) had multivisceral resections and 63/112 (56%) were completely resected (R0). 26/72 (36%) were clinical responders and 30 patients had a favourable PPS. Median survival was 20.0 months. Survival was significantly prolonged by resection, especially complete resection, and by preoperative CTx (all p = 0.001). Multivisceral resection, type or number of metastases, or primary tumour localization had no impact on survival. In patients undergoing preoperative CTx, clinical response and the PPS influenced survival significantly. In R0 resected patients, preoperative CTx, clinical response and the PPS remained prognostic. CONCLUSION: Primary resection without preoperative CTx is not appropriate for metastatic EGA. Subgroups of patients with a favourable PPS with response to CTx may be good candidates for surgical resection in metastatic oesophago-gastric cancer.

Distribution of isoforms of the microtubule-associated protein tau in grey and white matter areas of human brain: a two-dimensional gelelectrophoretic analysis.

The microtubule-associated protein tau in human brain consists of six molecular isoforms derived from a single gene by alternative mRNA-splicing and further modified by posttranslational processing. In the present study, the distribution of tau isoforms in grey and white matter of human temporal cortex was investigated by two-dimensional gelelectrophoresis. More than 80 isoforms were detected. The pattern of isoforms obtained after treatment with alkaline phosphatase was still more complex than those of recombinant tau, indicating that posttranslational modifications other than phosphorylation contribute to the molecular heterogeneity of tau. The tau isoform D according to Goedert containing four tubulin-binding regions shown to promote tubulin polymerisation most efficiently was present in higher amounts in white as compared to grey matter. The pattern of isoform distribution was not significantly altered in Alzheimer's disease. It is concluded that molecular isoforms that differ in their tubulin-binding characteristics are differentially distributed in subcellular neuronal compartments and/or neuronal types.

Identification of mouse crystallins in 2D protein patterns by sequencing and mass spectrometry. Application to cataract mutants.

The eye lens proteins of the mouse were separated into 1940 polypeptide spots by two-dimensional electrophoresis in large gels. All 16 crystallins ubiquitous in mammals were identified by protein sequencing and mass spectrometry except for (gamma)-F, which shows an almost identical sequence with (gamma)-E. Two crystallins, (beta)-A2 and (gamma)-S, were shown for the first time to occur in the mouse lens. An investigation of the murine cataract mutant Cat2(nop)((gamma)-B gene) demonstrated that a monogenic mutation might affect a broad spectrum of proteins.

Comparison of the effects of 5- and 6-HOAt on model peptide coupling reactions relative to the cases for the 4- and 7-Isomers.

Synthesis of 5- and 6-HOAt has completed the full set of the four HOAt isomers derived from HOBt by insertion of a single nitrogen atom in the benzenoid nucleus. Comparison of the reactivity of all four isomers in model peptide coupling reactions has confirmed the unique character of the 7-isomer in promoting selectivity and maintaining configuration at the reactive carboxylic acid residue.

Fluorescent dual colour 2D-protein gel electrophoresis for rapid detection of differences in protein pattern with standard image analysis software.

The use of two different fluorescent dyes in two-dimensional (2D) polyacrylamide gel electrophoresis was recently described and termed difference gel electrophoresis (DIGE). Thereby differences between protein samples could be accomplished by fluorescently tagging the samples with different dyes as well as co-separation and visualisation in a single gel. We adapted this method to the ampholyte technique, using newly available fluorescent dyes and three common image software systems for analysis. Working with protein lysates from tumour cell lines with defined added proteins we found that the technique is reproducible, sensitive and fast, because it circumvents the necessity of matching several 2D gels. This is mainly due to the fact that the generated images from the two different fluorescent channels could be superimposed by standard image analysis, so that changes in the protein pattern could be easily detected either by a different colour or by comparing grey values of corresponding spots. This method will be especially helpful in comparing proteins from normal and tumour tissue to highlight changes in genesis and progression in cancer.

Mutagenicity testing on non-selectively cloned Chinese hamster ovary cells with the protein-mapping method.

Chemical mutagenesis was studied on Chinese hamster ovary cells by protein mapping. Cell cultures were treated with methylnitrosourea and the cells were cloned in non-selective media. The proteins of single clones were separated by 2-dimensional electrophoresis and analysed for qualitative (electrophoretic mobility) and quantitative (staining intensity; presence/absence) changes in the protein patterns. The investigation included 26 clones derived from treated cells and 26 control clones. The total number of gene loci tested was calculated from the number of protein spots analysed: it amounted to about 33 800. The protein patterns revealed 2 alterations defined as qualitative variant proteins. No alteration of this type was found in the control group. The frequency of quantitative variant proteins was increased by more than 100% compared with the control group. Our results and theoretical considerations suggest that the cellular concentration of single proteins offers a sensitive parameter for mutagenicity testing.

Survey on neurosurgery subspecialty fellowship training. Congress of Neurological Surgeons Education Committee.

BACKGROUND: The ongoing controversy on the certification of neurosurgery subspecialties has not been settled. There has been no detailed report on why a resident chooses to undergo further training in the form of a postgraduate fellowship. A survey was devised to investigate the reasons, as well as factors, that prompt the resident to pursue fellowship training. METHODS: The names of the surveyed residents were obtained from the Congress of Neurological Surgeons database, and the names of the neurosurgery fellows were obtained from individual program coordinators by phone. A survey, a cover letter, and a return envelope were mailed to each prospective respondent. The data were entered on the Paradox for Windows program, and multiple queries were run to obtain tabulated results. RESULTS: The overwhelming majority (84.6%) of the resident respondents considered fellowship a possibility. Academic medicine was also the choice of career for most (60.3%). The most popular reported fellowships were spine (25.6%), pediatric (16.5%), and vascular (16.1%). The three top reasons for pursuing fellowship training were "personal interest for knowledge," "job market demand," and "academic prestige." "Inadequate training during residency" was a distant fourth. For respondents citing "inadequate training during residency" as one of the top three reasons, there were proportionally higher respondents in the fields of peripheral nerve, endovascular, and skull base neurosurgeries. CONCLUSION: A significant number of residents consider fellowship a way to further their personal interest and knowledge, as well as increase their marketability. Relatively few from the surveyed group considered their residency training experience deficient in the subspecialty areas, with the exception of peripheral nerve, endovascular, and possibly skull base neurosurgery.

In serum veritas-in serum sanitas? Cell non-autonomous aging compromises differentiation and survival of mesenchymal stromal cells via the oxidative stress pathway.

Even tissues capable of complete regeneration, such as bone, show an age-related reduction in their healing capacity. Here, we hypothesized that this decline is primarily due to cell non-autonomous (extrinsic) aging mediated by the systemic environment. We demonstrate that culture of mesenchymal stromal cells (MSCs) in serum from aged Sprague-Dawley rats negatively affects their survival and differentiation ability. Proteome analysis and further cellular investigations strongly suggest that serum from aged animals not only changes expression of proteins related to mitochondria, unfolded protein binding or involved in stress responses, it also significantly enhances intracellular reactive oxygen species production and leads to the accumulation of oxidatively damaged proteins. Conversely, reduction of oxidative stress levels in vitro markedly improved MSC function. These results were validated in an in vivo model of compromised bone healing, which demonstrated significant increase regeneration in aged animals following oral antioxidant administration. These observations indicate the high impact of extrinsic aging on cellular functions and the process of endogenous (bone) regeneration. Thus, addressing the cell environment by, for example, systemic antioxidant treatment is a promising approach to enhance tissue regeneration and to regain cellular function especially in elderly patients.

Xeno-kidney transplantation: from idea to reality.

Although kidney transplantation is a widely used therapy for chronic renal failure, not all patients can be transplanted due to the limited numbers of organ donations. A possible solution could be xenogenic kidney transplantation. Herein we have described the present state, problems and possible solutions using xenograft treatments.