Near-infrared photoabsorption by C60 dianions in a storage ring

We present a detailed study of the electronic structure and the stability of C(60) dianions in the gas phase. Monoanions were extracted from a plasma source and converted to dianions by electron transfer in a Na vapor cell. The dianions were then stored in an electrostatic ring, and their near-infrared absorption spectrum was measured by observation of laser induced electron detachment. From the time dependence of the detachment after photon absorption, we conclude that the reaction has contributions from both direct electron tunneling to the continuum and vibrationally assisted tunneling after internal conversion. This implies that the height of the Coulomb barrier confining the attached electrons is at least approximately 1.5 eV. For C(60)(2-) ions in solution electron spin resonance measurements have indicated a singlet ground state, and from the similarity of the absorption spectra we conclude that also the ground state of isolated C(60)(2-) ions is singlet. The observed spectrum corresponds to an electronic transition from a t(1u) lowest unoccupied molecular orbital (LUMO) of C(60) to the t(1g) LUMO+1 level. The electronic levels of the dianion are split due to Jahn-Teller coupling to quadrupole deformations of the molecule, and a main absorption band at 10,723 cm(-1) corresponds to a transition between the Jahn-Teller ground states. Also transitions from pseudorotational states with 200 cm(-1) and (probably) 420 cm(-1) excitation are observed. We argue that a very broad absorption band from about 11,500 cm(-1) to 13,500 cm(-1) consists of transitions to so-called cone states, which are Jahn-Teller states on a higher potential-energy surface, stabilized by a pseudorotational angular momentum barrier. A previously observed, high-lying absorption band for C(60)(-) may also be a transition to a cone state.

Cholinergic potentiation of the meal-related rise in ACTH and cortisol concentrations in men

The present study examined the influence of physostigmine, an acetylcholine esterase inhibitor, on the secretory activity of the hypothalamo-pituitary-adrenocortical (HPA)--axis under basal (experiment I) and stimulated (experiment II) conditions in young healthy men. In a third experiment, the effect of scopolamine, a muscarinic acetylcholine receptor antagonist, on HPA secretory activity after physiological stimulation was tested. The experiments started between 09.00 and 10.00 a.m.. After a resting period of 1.5 h, either physostigmine (0.0125 mg per kg body weight soluted in isotonic saline) or placebo (saline) was infused within 15 min. In experiment I subjects (n = 7) remained fasting while in experiment II (n = 18) a standardized lunch was offered after the infusion. Experiment III (n = 7) was designed as experiment II but instead of physostigmine, scopolamine or placebo (0.5 mg) was subcutaneously injected 105 min before the meal. Blood for the determination of ACTH and cortisol was drawn in regular intervals during the experiments. Physostigmine did not change basal ACTH and cortisol secretion per se, excluding activation of basal HPA secretion due to acetylcholineesterase inhibition and its non specific side effects. Meal intake stimulated ACTH and cortisol secretion which was significantly enhanced when physostigmine was administered (p < 0.05). Scopolamine did not influence the meal related ACTH and cortisol secretion. These findings demonstrate that cholinergic neurotransmission is able to increase ACTH and cortisol concentrations in humans. This effect seems to be complementary to other stimulatory neurotransmitter systems, and is functional during stimulated HPA secretory activity and not under basal conditions.

Molecular systematics of the cotton root rot pathogen, Phymatotrichopsis omnivora

Cotton root rot is an important soilborne disease of cotton and numerous dicot plants in the south-western United States and Mexico. The causal organism, Phymatotrichopsis omnivora (= Phymatotrichum omnivorum), is known only as an asexual, holoanamorphic (mitosporic) fungus, and produces conidia resembling those of Botrytis. Although the corticoid basidiomycetes Phanerochaete omnivora (Polyporales) and Sistotrema brinkmannii (Cantharellales; both Agaricomycetes) have been suggested as teleomorphs of Phymatotrichopsis omnivora, phylogenetic analyses of nuclear small- and large-subunit ribosomal DNA and subunit 2 of RNA polymerase II from multiple isolates indicate that it is neither a basidiomycete nor closely related to other species of Botrytis (Sclerotiniaceae, Leotiomycetes). Phymatotrichopsis omnivora is a member of the family Rhizinaceae, Pezizales (Ascomycota: Pezizomycetes) allied to Psilopezia and Rhizina.

Geriatric assessment of older adults with cancer: Baseline data from a 500 patient multicenter study

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Background: As the cancer population ages, a brief, comprehensive measure is needed to characterize the “functional age” of a patient, in order to optimize treatment decisions and evaluate outcomes based on factors other than chronological age. A geriatric assessment (GA) evaluates factors other than age that predict morbidity and mortality in older adults. The goals of this study are to describe the results of a GA performed in 500 older adults with cancer from 7 participating institutions and to evaluate the feasibility of completing this assessment in oncology practice. Methods: The GA is comprised of validated measures of functional status, comorbidity, cognition, psychological status, social functioning and support, and nutritional status (Hurria et al, Cancer 2005). The GA was completed prior to the start of a new chemotherapy regimen in patients age ≥ 65 with a solid tumor or lymphoma. Results: 500 patients (mean age 73; range 65–91) completed the GA. The most common tumor types were lung (29%), GI (29%) and breast/gyn (22%) cancer; 57% had stage IV disease. The GA revealed that 41% of patients needed assistance with instrumental activities of daily living despite a mean physician-reported KPS of 85 (range 50–100), 92% had ≥1 comorbid medical conditions (mean 2.5; range 0–9), 95% took ≥ 1 medications (mean 5; range 0–23), 16% had ≥ 1 falls in the past 6 months, 6% had gross cognitive impairment on the Blessed Orientation-Memory-Concentration Test, and 39% had > 5% weight loss in the past 6 months. The mean time to complete the GA was 27 minutes (range 10–80); 94% were satisfied with the GA length and 70% were able to complete the GA without assistance. Multivariate logistic regression identified the following sociodemiographic and disease variables predict the need for assistance with completion of the GA: age ≥ 80 (p=0.02), high school education or less (p<0.01), non-white race (p<0.01), and the presence of metastatic disease (p=0.01). Conclusions: This brief GA is largely self-administered, can be completed by the majority of older patients without assistance, and identifies important deficits and problems that may impact morbidity and mortality. Prospective data are being acquired to identify factors in the GA that predict chemotherapy toxicity in older adults with cancer.

No significant financial relationships to disclose.

Subcutaneous versus intravenous immunoglobulin in multifocal motor neuropathy: a randomized, single-blinded cross-over trial

BACKGROUND AND PURPOSE

For treatment of multifocal motor neuropathy (MMN), we hypothesized that (i) infusion of equivalent dosages of subcutaneous immunoglobulin (SCIG) is as effective as intravenous immunoglobulin (IVIG) and that (ii) subcutaneous infusion at home is associated with a better quality of life.

METHODS

In a randomized single-blinded cross-over study, nine IVIG responsive patients were allocated to receive either SCIG or IVIG for a period equivalent to three IVIG treatment intervals and, subsequently, crossed over to the other treatment. Primary end-points were (i) dynamometric strength of affected muscles and (ii) the SF-36 quality of life questionnaire.

RESULTS

The two treatments were equally effective, the mean change in muscle strength after SCIG being 3.6% (95% CI -3.6% to 10.9%) vs. 4.3% (-1.3% to 10.0%) after IVIG (P = 0.86). One patient had sustained erythema and oedema at the injection sites for a few weeks. All other adverse effects during SCIG were mild and transient. No differences between treatments of health-related quality of life occurred.

CONCLUSION

In MMN, short-term subcutaneous infusion of immunoglobulin is feasible, safe and as effective as intravenous infusion. Subcutaneous administration is an alternative option that adds flexibility to the treatment schedule.

Regulation of stem cell differentiation by histone methyltransferases and demethylases

The generation of different cell types from stem cells containing identical genetic information and their organization into tissues and organs during development is a highly complex process that requires defined transcriptional programs. Maintenance of such programs is epigenetically regulated and the factors involved in these processes are often essential for development. The activities required for cell-fate decisions are frequently deregulated in human tumors, and the elucidation of the molecular mechanisms that regulate these processes is therefore important for understanding both developmental processes and tumorigenesis.

Autophagy regulates selective HMGB1 release in tumor cells that are destined to die

Macroautophagy (hereafter referred to as autophagy) can increase or decrease the amount of cell death in response to various stimuli. To test if autophagy also controls the characteristics associated with dying cells, we studied tumor cell killing by Epidermal Growth Factor Receptor (EGFR)-targeted diphtheria toxin (DT-EGF). DT-EGF kills epithelial and glioblastoma tumor cells with similar efficiency but by different mechanisms that depend on whether the cells activate autophagy when treated with the drug. Dying cells in which autophagy is induced selectively release the immune modulator HMGB1 without causing lysis of the cell membrane and classical necrosis. Conversely, cells that are killed by DT-EGF where autophagy is blocked, activate caspases but retain HMGB1. These data suggest that it may be feasible to manipulate the immunogenicity of dying cells by increasing or decreasing autophagy.

Movement detection impaired in patients with knee osteoarthritis compared to healthy controls: a cross-sectional case-control study

The purpose of this study was to clarify whether osteoarthritis (OA) patients have a localized or a generalized reduction in proprioception. Twenty one women with knee OA (mean age [SD]: 57.1 [12.0] years) and 29 healthy women (mean age [SD]: 55.3 [10.1] years) had their joint position sense (JPS) and threshold to detection of a passive movement (TDPM) measured in both knees and elbows. JPS was measured as the participant's ability to actively reproduce the position of the elbow and knee joints. TDPM was measured as the participant's ability to recognize a passive motion of the elbow and knee joints. The absolute error (AE) for JPS (i.e., absolute difference in degrees between target and estimated position) and for TDPM (i.e., the difference in degrees at movement start and response when recognizing the movement) was calculated. For TDPM a higher AE (mean [SE]) was found in the involved knees in patients than in the matched knees of healthy participants (AE: 2.41 degrees [0.20 degrees] versus 1.47 degrees [0.14], p=0.001). The same held true for the non-involved knees between OA and healthy subjects (AE: 2.20 degrees [0.20 degrees] versus 1.57 degrees [0.14 degrees], p=0.016). Furthermore TDPM was higher in OA patients' right elbows compared to healthy participants' right elbows (AE: 2.15 degrees [0.20 degrees] versus 1.45 degrees [0.15 degrees], p=0.011). No significant difference between healthy women and OA patients regarding the left elbow for TDPM, or JPS was observed. The present age-controlled, cross-sectional study suggests that there is an increase in threshold to detection of a passive motion in knees and elbows for patients with knee OA. This indicates that OA may be associated with a generalized defect in proprioception with possible implications for the pathogenesis of the joint degeneration.

A compact 7-cell Si-drift detector module for high-count rate X-ray spectroscopy

A new Si-drift detector module for fast X-ray spectroscopy experiments was developed and realized. The Peltier-cooled module comprises a sensor with 7 × 7-mm² active area, an integrated circuit for amplification, shaping and detection, storage, and derandomized readout of signal pulses in parallel, and amplifiers for line driving. The compactness and hexagonal shape of the module with a wrench size of 16mm allow very short distances to the specimen and multi-module arrangements. The power dissipation is 186mW. At a shaper peaking time of 190 ns and an integration time of 450 ns an electronic rms noise of ~11 electrons was achieved. When operated at 7 °C, FWHM line widths around 260 and 460 eV (Cu-K_α) were obtained at low rates and at sum-count rates of 1.7 MHz, respectively. The peak shift is below 1% for a broad range of count rates. At 1.7-MHz sum-count rate the throughput loss amounts to 30%.