On the energetics of P–P bond dissociation of sterically strained tetraamino-diphosphanes

Thermochemical data for the homolytic P–P bond fission in tetraaminodiphosphanes (R₂N)₂P–P(NR₂)₂ were determined experimentally and computationally. The results confirm that radical formation is favoured by entropic and structural relaxation effects, and disfavoured by dispersion forces. Unlike aminophosphenium cations, the radicals display no strong preference for a planar (R₂N)₂P unit.

The International Association for the Study of Lung Cancer Lung Cancer Staging Project: Proposals for the Revision of the Clinical and Pathologic Staging of Small Cell Lung Cancer in the Forthcoming Eighth Edition of the TNM Classification for Lung Cancer

INTRODUCTION

Small cell lung cancer (SCLC) is commonly classified as either limited or extensive, but the Union for International Cancer Control TNM Classification of Malignant Tumours seventh edition (2009) recommended tumor, node, and metastasis (TNM) staging based on analysis of the International Association for the Study of Lung Cancer (IASLC) database.

METHODS

Survival analyses were performed for clinically and pathologically staged patients presenting with SCLC from 1999 through 2010. Prognosis was compared in relation to the TNM seventh edition staging to serve as validation and analyzed in relation to proposed changes to the T descriptors found in the eighth edition.

RESULTS

There were 5002 patients: 4848 patients with clinical and 582 with pathological stages. Among these, 428 had both. Survival differences were confirmed for T and N categories and maintained in relation to proposed revisions to T descriptors for seventh edition TNM categories and proposed changes in the eighth edition. There were also survival differences, notably at 12 months, in patients with brain-only single-site metastasis (SSM) compared to SSM at other sites, and SSM without a pleural effusion showed a better prognosis than other patients in the M1b category.

CONCLUSION

We confirm the prognostic value of clinical and pathological TNM staging in patients with SCLC, and recommend continued usage for SCLC in relation to proposed changes to T, N, and M descriptors for NSCLC in the eighth edition. However, for M descriptors, it remains uncertain whether survival differences in patients with SSM in the brain simply reflect better treatment options rather than better survival based on anatomic extent of disease.

[Investigation of color vision in acute unilateral optic neuritis using a web-based color vision test]

BACKGROUND

In acute unilateral optic neuritis (ON) color vision defects combined with a decrease in visual acuity and contrast sensitivity frequently occur. This study investigated whether a web-based color vision test is a reliable detector of acquired color vision defects in ON and, if so, which charts are particularly suitable.

METHODS

In 12 patients with acute unilateral ON, a web-based color vision test ( www.farbsehtest.de ) with 25 color plates (16 Velhagen/Broschmann and 9 Ishihara color plates) was performed. For each patient the affected eye was tested first and then the unaffected eye.

RESULTS

The mean best-corrected distance visual acuity (BCDVA) in the ON eye was 0.36 ± 0.20 and 1.0 ± 0.1 in the contralateral eye. The number of incorrectly read plates correlated with the visual acuity. For the ON eye a total of 134 plates were correctly identified and 166 plates were incorrectly identified, while for the disease-free fellow eye, 276 plates were correctly identified and 24 plates were incorrectly identified. Both of the blue/yellow plates were identified correctly 14 times and incorrectly 10 times using the ON eye and exclusively correctly (24 times) using the fellow eye. The Velhagen/Broschmann plates were incorrectly identified significantly more frequently in comparison with the Ishihara plates. In 4 out of 16 Velhagen/Broschmann plates and 5 out of 9 Ishihara plates, no statistically significant differences between the ON eye and the fellow eye could be detected.

CONCLUSION

The number of incorrectly identified plates correlated with a decrease in visual acuity. Red/green and blue/yellow plates were incorrectly identified significantly more frequently with the ON eye, while the Velhagen/Broschmann color plates were incorrectly identified significantly more frequently than the Ishihara color plates. Thus, under defined test conditions the web-based color vision test can also be used to detect acquired color vision defects, such as those caused by ON. Optimization of the test by altering the combination of plates may be a useful next step.

Probing hydrogen bonding orbitals: resonant inelastic soft X-ray scattering of aqueous NH3

Resonant inelastic soft X-ray scattering was used to probe the hydrogen bonding orbitals in aqueous ammonia.

[One-year results of small incision lenticule extraction (SMILE) in myopia]

BACKGROUND

This clinical trial is focused on the 12-month results of a new method for refractive correction in myopia, called "small incision lenticule extraction" (SMILE).

PATIENTS AND METHODS

In a prospective study 91 eyes were treated with the new refractive procedure and the results were published after 6 months. A lenticule of intrastromal corneal tissue is cut utilising the Carl Zeiss Meditec AG (Jena, Germany) VisuMax femtosecond laser system. Thereafter, this lenticule is manually removed without lifting a flap. 55 eyes of 33 patients volunteered for a 12-month follow-up. UCVA and BSCVA after 12 months, objective and manifest refraction as well as slit-lamp examination and late side effects were documented.

RESULTS

55 eyes of 33 patients were re-examined in this study 12 months after surgery. The spherical equivalent before surgery was - 4.66 (± 1.75) D; after 12 months - 0.11 (± 0.42) D was manifest. No significant change was observed compared to the 6-month control. Starting with UCVA of 0.1 (± 0.06) before surgery. UCVA was 1.02 (± 0.3) after 12 months. One eye lost more than two lines. All other patients did not have any late side effects.

CONCLUSION

The one-year results of this new procedure are encouraging. Especially stability of the correction of myopia and myopic astigmatism with the SMILE procedure is very good.

[Morphological analysis of corneal refractive lenticules--is there a correlation with refractive results?]

BACKGROUND

ReLEx®flex is a corneal refractive procedure performed by removing corneal lenticules with a femtosecond (fs) laser system. Using electron microscopy, tissue parameters of extracted lenticules were analysed for potential correlations to the refractive results. Furthermore, the effect of previous contact lens (CL) wear on refractive stability (regression) was tested.

PATIENTS AND METHODS

19 lenticules from 11 patients (age 24-56 years, 8 f, 3 m) were prepared for EM. The central areas of the samples were photographed and the distance between the collagen fibres and their diameters were digitally measured. ANOVA analysis was used to correlate postoperative refractional stability with time of preoperative CL use, fibre diameter and the coefficient of variation (CV) of fibre distance.

RESULTS

14 of 19 lenticules were from patients who had worn CL preoperatively. The cumulative duration of CL wear averaged around 31.2 ± 35.5 thousand hours. Preoperative CL use significantly influenced the postoperative regression: the longer time patients had worn CL, the greater was the regression towards myopia (p = 0.01). Additionally, the morphological parameters collagen fibre diameter (p = 0.09) and CV of fibre distance (p = 0.07) had an impact on regression.

CONCLUSIONS

Prolonged CL use and alterations in ultrastructural patterns affected the refractive stability after ReLExflex. Although the pathophysiological relationships between CL use, corneal morphological parameters, and refractive stability are still poorly understood, these findings could potentially be used as prognostic markers for postoperative refraction after ReLExflex.

Setup for in situ investigation of gases and gas/solid interfaces by soft x-ray emission and absorption spectroscopy

We present a novel gas cell designed to study the electronic structure of gases and gas/solid interfaces using soft x-ray emission and absorption spectroscopies. In this cell, the sample gas is separated from the vacuum of the analysis chamber by a thin window membrane, allowing in situ measurements under atmospheric pressure. The temperature of the gas can be regulated from room temperature up to approximately 600 °C. To avoid beam damage, a constant mass flow can be maintained to continuously refresh the gaseous sample. Furthermore, the gas cell provides space for solid-state samples, allowing to study the gas/solid interface for surface catalytic reactions at elevated temperatures. To demonstrate the capabilities of the cell, we have investigated a TiO2 sample behind a mixture of N2 and He gas at atmospheric pressure.

Provision of long-acting reversible contraception in HIV-prevalent countries: results from nationally representative surveys in southern Africa

OBJECTIVE

To analyse the current provision of long-acting reversible contraception (LARC) and clinician training needs in HIV-prevalent settings.

DESIGN

Nationally representative survey of clinicians.

SETTING

HIV-prevalent settings in South Africa and Zimbabwe.

POPULATION

Clinicians in South Africa and Zimbabwe.

METHODS

Nationally representative surveys of clinicians were conducted in South Africa and Zimbabwe (n = 1444) to assess current clinical practice in the provision of LARC in HIV-prevalent settings. Multivariable logistic regression was used to analyse contraceptive provision and clinician training needs.

MAIN OUTCOME MEASURE

Multivariable logistic regression of contraceptive provision and clinician training needs.

RESULTS

Provision of the most effective reversible contraceptives is limited: only 14% of clinicians provide copper intrauterine devices (IUDs), 4% levonorgestrel-releasing IUDs and 16% contraceptive implants. Clinicians' perceptions of patient eligibility for IUD use were overly restrictive, especially related to HIV risks. Less than 5% reported that IUDs were appropriate for women at high risk of HIV or for HIV-positive women, contrary to evidence-based guidelines. Only 15% viewed implants as appropriate for women at risk of HIV. Most clinicians (82%), however, felt that IUDs were underused by patients, and over half desired additional training on LARC methods. Logistic regression analysis showed that LARC provision was largely restricted to physicians, hospital settings and urban areas. Results also showed that clinicians in rural areas and clinics, including nurses, were especially interested in training.

CONCLUSIONS

Clinician competency in LARC provision is important in southern Africa, given the low use of methods and high rates of unintended pregnancy among HIV-positive and at-risk women. Despite low provision, clinician interest is high, suggesting the need for increased evidence-based training in LARC to reduce unintended pregnancy and associated morbidities.

Novel signalling mechanisms and targets in renal ischaemia and reperfusion injury

Acute kidney injury (AKI) induced by ischaemia and reperfusion (I/R) injury is a common and severe clinical problem. Vascular dysfunction, immune system activation and tubular epithelial cell injury contribute to functional and structural deterioration. The search for novel therapeutic interventions for I/R-induced AKI is a dynamic area of experimental research. Pharmacological targeting of injury mediators and corresponding intracellular signalling in endothelial cells, inflammatory cells and the injured tubular epithelium could provide new opportunities yet may also pose great translational challenge. Here, we focus on signalling mediators, their receptors and intracellular signalling pathways which bear potential to abrogate cellular processes involved in the pathogenesis of I/R-induced AKI. Sphingosine 1 phosphate (S1P) and its respective receptors, cytochrome P450 (CYP450)-dependent vasoactive eicosanoids, NF-κB- and protein kinase-C (PKC)-related pathways are representatives of such 'druggable' pleiotropic targets. For example, pharmacological agents targeting S1P and PKC isoforms are already in clinical use for treatment for autoimmune diseases and were previously subject of clinical trials in kidney transplantation where I/R-induced AKI occurs as a common complication. We summarize recent in vitro and in vivo experimental studies using pharmacological and genomic targeting and highlight some of the challenges to clinical application of these advances.

Unsafe abortion after legalisation in Nepal: a cross-sectional study of women presenting to hospitals

OBJECTIVE

To investigate abortion practices of Nepali women requiring postabortion care.

DESIGN

Cross-sectional study.

SETTING

Four tertiary-care hospitals in urban and rural Nepal.

SAMPLE

A total of 527 women presenting with complications from induced abortion in 2010.

METHODS

Women completed questionnaires on their awareness of the legal status of abortion and their abortion-seeking experiences. The method of induction and whether the abortion was obtained from an uncertified source was documented. Multivariable logistic regression was used to identify associated factors.

MAIN OUTCOME MEASURES

Induction method; uncertified abortion source.

RESULTS

In all, 234 (44%) women were aware that abortion was legal in Nepal. Medically induced abortion was used by 359 (68%) women and, of these, 343 (89%) took unsafe, ineffective or unknown substances. Compared with women undergoing surgical abortion, women who had medical abortion were more likely to have obtained information from pharmacists (161/359, 45% versus 11/168, 7%, adjusted odds ratio [aOR] 8.1, 95% confidence interval 4.1-16.0) and to have informed no one about the abortion (28/359, 8% versus 3/168, 2%, aOR 5.5, 95% CI 1.1-26.9). Overall, 291 (81%) medical abortions and 50 (30%) surgical abortions were obtained from uncertified sources; these women were less likely to know that abortion was legal (122/341, 36% versus 112/186, 60%, aOR 0.4, 95% CI 0.2-0.7) and more likely to choose a method because it was available nearby (209/341, 61% versus 62/186, 33%, aOR 2.5, 95% CI 1.5-4.3), compared with women accessing certified sources.

CONCLUSIONS

Among women presenting to hospitals in Nepal with complications following induced abortion of pregnancy, the majority had undergone medically induced abortions using unknown substances acquired from uncertified sources. Women using medications and those accessing uncertified providers were less aware that abortion is now legal in Nepal. These findings highlight the need for continued improvements in the provision and awareness of abortion services in Nepal.