Temperature/light dependent development of selective resistance to photoinhibition of photosystem I

BACKGROUND: Circulating magnesium exists in the ionized state and in the undissociated form, either bound to albumin, or complexed to various anions. Until recently, only the measurement of total plasma magnesium has been possible. Now circulating ionized magnesium can be assessed as well. METHODS: Total and ionized plasma magnesium were determined in 43 patients on maintenance hemodialysis (dialysate composition: calcium 1.75 mmol/l, magnesium 0.75 mmol/l) before a dialysis session and in a group of 23 healthy subjects. RESULTS: The total (1.16 [1.03-1.31] versus 0.81 [0.78-0.89] mmol/l; median and interquartile range) and the ionized (0.71 [0.66-0.78] versus 0.54 [0.53-0.59] mmol/l) plasma magnesium levels were significantly higher (p < 0.01) and the ionized plasma magnesium fraction lower (0.61 [0.58-0.65] versus 0.67 [0.64-0.70]; p < 0.02) in patients than in controls. CONCLUSION: The determination of circulating ionized magnesium using selective electrodes is an attractive method to evaluate extracellular magnesium in kidney disease.     

Cloning and characterization of the guinea pig eosinophil eotaxin receptor, C-C chemokine receptor-3: blockade using a monoclonal antibody in vivo

Certain C-C chemokines, signaling via the eotaxin receptor C-C chemokine receptor-3 (CCR3), are thought to be central mediators of eosinophil accumulation in allergic inflammation. To investigate the role of CCR3 in vivo, we cloned the guinea pig eotaxin receptor (guinea pig CCR3) from a genomic DNA library. We isolated a single-exon open reading frame coding for a 358-amino acid chemokine receptor protein with 67 and 69% homology to human and murine CCR3, respectively. When expressed in stable transfectants, this receptor bound 125I-labeled guinea pig eotaxin, 125I-labeled human monocyte chemotactic protein-3, and 125I-labeled human RANTES. In chemotaxis assays, guinea pig CCR3 transfectants responded only to guinea pig eotaxin, with a maximal effect at 100 nM. mAbs were raised that bound selectively to both guinea pig CCR3 transfectants and guinea pig eosinophils. One of these mAbs, 2A8, blocked both ligand binding to transfectants and their chemotaxis in response to eotaxin. The Ab also inhibited chemotaxis and the elevation of cytosolic calcium in guinea pig eosinophils in response to eotaxin. F(ab')2 fragments of 2A8 were prepared that retained the ability to inhibit eosinophil calcium responses to eotaxin. Pretreatment of (111)In-labeled eosinophils in vitro with F(ab')2 2A8 selectively inhibited their accumulation in response to eotaxin in vivo. These data demonstrate that functional blockade of eosinophil chemokine receptors can be achieved in vivo and provide further support for the development of novel anti-inflammatory drugs targeting eosinophil recruitment through chemokine receptor antagonism.     

Trauma center 2000. How many and which trauma centers does Europe need around the year 2000?

The treatment of severely injured patients is a challenge for preclinical and clinical treatment concepts, causing financial aspects of increasing importance for the German health care system. A total of 32,500 polytraumatized patients (PTS III and IV) are managed in trauma center levels I-IV in Germany. Trauma center levels I or II are by definition capable of supporting the full range of treatment for the severely injured. With the baseline calculation of 64,000 DM per patient and 104 polytrauma treated per year in the Berlin Virchow Clinic, 6.66 million DM primary costs must be spent for treatment. The total annual costs of this center are nearly 24 million DM for emergency cases and 7 million DM fixed costs per year, for a trauma center level I. In Europe the distribution of trauma center levels I or II is sufficient and can be specified with 1 center per 1 million inhabitants. Nevertheless, the european air medical service could support more intensive use of these central trauma institutions. This was shown by comparing the number of polytrauma patients and the number of trauma centers. Less then half of these patients are treated in levels I or II trauma centers. The financial pressure on the health system and the rising quality must lead to better utilization of trauma centers. To meet this goal a annual treatment rate of 300-400 polytrauma patients should be aimed at. The claim of the American College of Surgeons that a trauma surgeon should treat 50 severely injured patients per year would then be possible.     

Lost in citation: Vanishing visibility of senior authors

The senior author is usually last on the byline of scientific publications, yet generally has made the second most important contribution. The explosion in author number per scientific paper, has necessitated limits on the number of authors allowed in cited references, frequently resulting in senior author truncation. Would potential visibility gained from citations in top-tier journals be offset by senior author omission? We found evidence for this in a sample of 208 journals, showing significant associations between author limits in cited references and various measures of journal quality. These associations, however, differed among biological science, physical science, and interdisciplinary journals.     

An analysis of morning report at a pediatric hospital

The purpose of this study was to determine the types of cases residents select for morning report discussion and the educational value of postdischarge follow-up of unknown cases. Between April and December of 1994, at Cardinal Glennon Children's Hospital in St. Louis, Missouri, random, resident, and group-selected patients listed at morning report were followed up throughout hospitalization. Patients were categorized based upon whether or not their morning report and discharge diagnoses were the same or different. Patients discharged without a diagnosis were followed up by chart review at 6 months to determine whether a diagnosis had been made. Data were analyzed by Chi-square analysis with Bonfferoni adjustment factor for multiple comparisons. Residents were more than two times more likely to select cases for discussion in which the diagnosis changed during hospitalization (P < 0.01). The 6-month follow-up yielded new diagnoses in only 21% of previously unknown cases. We concluded that residents do an exceptional job of selecting difficult diagnostic cases for discussion at morning report. Postdischarge follow up of unknown cases adds little new information for discussion at morning report.     

Follistatin and activin A production by the male reproductive tract

Follistatin is a binding protein for the activin and inhibin family of hormones, regulating their biological activity. In the male reproductive tract, the interaction of these factors is likely to be involved in the regulation of the proliferation of several cell types. We have investigated the presence of follistatin and activin A in seminal plasma using specific immunoassays and have localized follistatin and activin/inhibin subunits in the adult human testis, prostate and seminal vesicle to establish their likely sources. High concentrations of immunoreactive follistatin were present in seminal plasma in normal men (mean 97.9 ng/ml; 1.43 ng/ml in peripheral plasma) and were similar in men with oligo/azoospermia and following vasectomy. Follistatin immunoreactivity was localized to both Leydig and Sertoli cells of the testis, and to epithelial cells of the prostate gland and seminal vesicle, which are likely to be the predominant sources of the hormone in seminal plasma. Activin A was also present in seminal plasma in normal men but was undetectable following vasectomy, thus deriving from the testis. Consistent with this finding, the betaA-subunit was immunolocalized in Sertoli and Leydig cells but was not present in seminal vesicle or prostate gland. The functional significance of the high concentrations of follistatin secreted into seminal plasma by the prostate gland and/or seminal vesicle is uncertain, but they may regulate the biological activity of testis-derived activin A and inhibin B.     

New Epoxy/Jeffamine networks modified with ionic liquids

Diglycidyl ether of Bisphenol A/Jeffamine D400 system was modified with 2.5 and 5.0 phr of ionic liquids based on imidazolium and phosphonium cations denoted N,N ′‐dioctadecyl‐imidazolium iodide, or octadecyl‐triphenylphosphonium iodide, [OdTPP][I], aiming to develop new networked materials with enhanced performance particularly in terms of mechanical properties and conductivity. The curing behavior was investigated by differential scanning calorimetry, suggesting that the presence of ionic liquids (ILs) accelerates the curing process of the epoxy system. Then, the networked materials were analyzed by dynamic mechanical analysis, and mechanical testing. The presence of the ILs did not affect the glass transition temperature but resulted in a decrease on the storage modulus. By transmission electron microscopy, we have highlighted that the ILs are not miscible inside the epoxy matrix. In fact, a phase separation in nanometric scale has been observed. Measurements of conductivity revealed that the system modified with [OdTPP][I] presented higher dielectric constant and higher electrical conductivity. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39834.     

Multi‐point monitoring of cross‐linking reactions

The feasibility of deploying optical fiber sensors to obtain qualitative and quantitative information on the cross‐linking characteristics of thermosetting resin systems has been demonstrated by a number of researchers. This article is concerned with the demonstration of a low‐cost fiber‐optic Fresnel sensor system for monitoring the cross‐linking reactions at multiple locations. Cross‐linking reactions can be influenced by a number of parameters including the stoichiometry of the resin and hardener, and the heat‐transfer rates in and out of the preform as a function of the cross‐section of the preform. In situations where there is a variation in the thickness of the preform or when large components are processed, a facility to monitor the cross‐linking reactions at multiple locations will be valuable because the rate and extent of the cross‐linking can be inferred. In this article, six Fresnel sensors were immersed in individual vials containing an epoxy/amine resin system and processed (cross‐linked) in an air‐circulating oven. One additional vial with a Fresnel sensor immersed in the neat epoxy resin (no hardener) was co‐located in the oven to enable the effect of temperature to be monitored. The feasibility of using the multiplexed Fresnel sensors for cure monitoring was demonstrated successfully. The sensors in the post‐cross‐linked samples were used to study the effects of heating and cooling cycles. The feasibility of detecting the glass transition temperature using the Fresnel sensor is discussed along with the factors that give rise to variability in the output Fresnel signals. © 2014 The Authors. Journal of Applied Polymer Science Published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41088.