Investigating charge-up and fragmentation dynamics of oxygen molecules after interaction with strong X-ray free-electron laser pulses

The X-ray-induced charge-up and fragmentation process of a small molecule is examined in great detail by measuring the molecular-frame photoelectron interference pattern in conjunction with other observables in coincidence.

Measuring the photoelectron emission delay in the molecular frame

How long does it take to emit an electron from an atom? This question has intrigued scientists for decades. As such emission times are in the attosecond regime, the advent of attosecond metrology using ultrashort and intense lasers has re-triggered strong interest on the topic from an experimental standpoint. Here, we present an approach to measure such emission delays, which does not require attosecond light pulses, and works without the presence of superimposed infrared laser fields. We instead extract the emission delay from the interference pattern generated as the emitted photoelectron is diffracted by the parent ion's potential. Targeting core electrons in CO, we measured a 2d map of photoelectron emission delays in the molecular frame over a wide range of electron energies. The emission times depend drastically on the photoelectrons' emission directions in the molecular frame and exhibit characteristic changes along the shape resonance of the molecule.

Photoelectron circular dichroism of O 1s-photoelectrons of uniaxially oriented trifluoromethyloxirane: energy dependence and sensitivity to molecular configuration

The photoelectron circular dichroism (PECD) of the O 1s-photoelectrons of trifluoromethyloxirane (TFMOx) is studied experimentally and theoretically for different photoelectron kinetic energies. The experiments were performed employing circularly polarized synchrotron radiation and coincident electron and fragment ion detection using cold target recoil ion momentum spectroscopy. The corresponding calculations were performed by means of the single center method within the relaxed-core Hartree-Fock approximation. We concentrate on the energy dependence of the differential PECD of uniaxially oriented TFMOx molecules, which is accessible through the employed coincident detection. We also compare the results for the differential PECD of TFMOx to those obtained for the equivalent fragmentation channel and similar photoelectron kinetic energy of methyloxirane (MOx), studied in our previous work. Thereby, we investigate the influence of the substitution of the methyl group by the trifluoromethyl group at the chiral center on the molecular chiral response. Finally, the presently obtained angular distribution parameters are compared to those available in the literature.

Prediction of Behavioral T/C Levels in Cochlear Implant Patients Based Upon Analysis of Electrode Impedances

BACKGROUND

Fitting cochlear implants in babies and noncooperative patients is cumbersome and time consuming. Therefore, objective parameters have been sought in order to predict the subjective threshold (T) and maximum comfort (C) levels. Measurements of the electrically evoked compound action potentials (ECAPs) have been widely used for this purpose, yet the correlation between these objective measures and the subjective T/C levels is weak to moderate.

PURPOSE

This article aims (1) to evaluate correlations between the subjective parameters of the fitting maps such as thresholds (T level) and maximum comfort levels (C level), the impedance of the electrode contacts, and the ECAP thresholds, and (2) to compare the value of the electrode impedances and the ECAP measures for prediction of the T/C levels.

RESEARCH DESIGN

Case review study in a quaternary otologic referral center.

STUDY SAMPLE

Ninety-eight consecutive CI patients were enrolled. The average age of the patients was 49 years. All patients were users of the Nucleus 24RECA (Freedom, Contour Advance-of-Stylet electrode) cochlear implant.

DATA COLLECTION AND ANALYSIS

Data on impedance of the electrode contacts and the behavioral T/C levels at the first fitting session (2-5 weeks after surgery) and at the 5th fitting session (4-6 months after surgery) have been retrospectively collected in 98 consecutive CI patients. Additionally, the intraoperative impedance values and the ECAP thresholds (tNRT) have been recorded.

RESULTS

Impedances of electrode contacts show significant strong negative correlations with the stabilized T/C levels at 4 to 6 months after implantation and are an important predictor for the behavioral T/C levels. They can explain R ² = 28 to 41% of the variability of the behavioral T/C levels. In multiple regression analysis electrode contact impedances can explain twice as much of the variability of the stabilized T/C levels than the tNRT values. The electrode impedances together with the tNRT values are able to explain R ² = 37 to 40% of the global variability of the T/C levels while the tNRT thresholds solely are able to explain only R ² = 5 to 14% of the T/C levels variability.

CONCLUSION

Impedances of electrode contacts correlate strongly with the stabilized behavioral T/C levels and may be used as an objective measure for fitting of cochlear implants.

Double Core-Hole Generation in O_{2} Molecules Using an X-Ray Free-Electron Laser: Molecular-Frame Photoelectron Angular Distributions

We report on a multiparticle coincidence experiment performed at the European X-ray Free-Electron Laser at the Small Quantum Systems instrument using a COLTRIMS reaction microscope. By measuring two ions and two electrons in coincidence, we investigate double core-hole generation in O_{2} molecules in the gas phase. Single-site and two-site double core holes have been identified and their molecular-frame electron angular distributions have been obtained for a breakup of the oxygen molecule into two doubly charged ions. The measured distributions are compared to results of calculations performed within the frozen- and relaxed-core Hartree-Fock approximations.

Observation of Photoion Backward Emission in Photoionization of He and N_{2}

We experimentally investigate the effects of the linear photon momentum on the momentum distributions of photoions and photoelectrons generated in one-photon ionization in an energy range of 300  eV≤E_{γ}≤40  keV. Our results show that for each ionization event the photon momentum is imparted onto the photoion, which is essentially the system's center of mass. Nevertheless, the mean value of the ion momentum distribution along the light propagation direction is backward-directed by -3/5 times the photon momentum. These results experimentally confirm a 90-year-old prediction.

Influence of the pre- or postlingual status of cochlear implant recipients on behavioural T/C-levels

INTRODUCTION

Previous auditory experience modifies the sensitivity of the auditory cortex to the afferent activity of the auditory pathways and may influence the threshold (T) and comfort (C) levels in patients receiving a cochlear implant (CI). Literature data on this particular topic is very scarce.

OBJECTIVE

This study aimed to evaluate the differences in T/C-levels between pre- and postlingually implanted cochlear implant patients.

METHODS

Retrospective case review in a quaternary otologic referral centre was performed. Data on the T/C-levels have been collected in 90 consecutive CI patients divided into 2 groups. Group 1 comprised 16 prelingually deaf children implanted between 8 months and 10 years of age. Group 2 comprised 74 postlingually deaf adults (average age of 62 years). All patients were users of the Nucleus 24RECA (Freedom, Contour Advance-of-Stylet electrode) cochlear implant. All measurements were performed at the fifth implant programming session at 4-6 months after surgery, when stable T/C thresholds have already been obtained.

RESULTS

The behavioural C-levels present important and statistically significant differences between the pre- and postlingually implanted patients for all electrode contacts that could reach 30 CL. For the T-levels the observed differences were smaller and statistically insignificant for most electrode contacts.

CONCLUSIONS

The previous auditory experience (pre- or postlingual deafness) seems to be an independent parameter influencing the T/C-levels in patients receiving a CI. Together with the electrode contact impedance and the contact position in the electrode array it can explain up to 37% of the variability in the definition of the C-levels. The fact that the stabilised C-levels measured 4-6 months postoperatively can be up to 30 CL higher in the prelingually deaf patients than in the postlingual ones results also in a much higher dynamic range observed in prelingual subjects. Therefore implant programming of the prelingual patients should be very cautious in order to avoid the risk of overstimulation.

Recoil-Induced Asymmetry of Nondipole Molecular Frame Photoelectron Angular Distributions in the Hard X-ray Regime

We investigate angular emission distributions of the 1s photoelectrons of N_{2} ionized by linearly polarized synchrotron radiation at hν=40  keV. As expected, nondipole contributions cause a very strong forward-backward asymmetry in the measured emission distributions. In addition, we observe an unexpected asymmetry with respect to the polarization direction, which depends on the direction of the molecular fragmentation. In particular, photoelectrons are predominantly emitted in the direction of the forward nitrogen atom. This observation cannot be explained via asymmetries introduced by the initial bound and final continuum electronic states of the oriented molecule. The present simulations assign this asymmetry to a novel nontrivial effect of the recoil imposed to the nuclei by the fast photoelectrons and high-energy photons, which results in a propensity for the ions to break up along the axis of the recoil momentum. The results are of particular importance for the interpretation of future experiments at x-ray free electron lasers operating in the few tens of keV regime, where such nondipole and recoil effects will be essential.

Photon-Momentum-Induced Molecular Dynamics in Photoionization of N_{2} at hν=40 keV

We investigate K-shell ionization of N_{2} at 40 keV photon energy. Using a cold target recoil ion momentum spectroscopy reaction microscope, we determine the vector momenta of the photoelectron, the Auger electron, and both N^{+} fragments. These fully differential data show that the dissociation process of the N_{2}^{2+} ion is significantly modified not only by the recoil momentum of the photoelectron but also by the photon momentum and the momentum of the emitted Auger electron. We find that the recoil energy introduced by the photon and the photoelectron momentum is partitioned with a ratio of approximately 30∶70 between the Auger electron and fragment ion kinetic energies, respectively. We also observe that the photon momentum induces an additional rotation of the molecular ion.

Soil net nitrogen mineralisation across global grasslands

Soil nitrogen mineralisation (Nmin), the conversion of organic into inorganic N, is important for productivity and nutrient cycling. The balance between mineralisation and immobilisation (net Nmin) varies with soil properties and climate. However, because most global-scale assessments of net Nmin are laboratory-based, its regulation under field-conditions and implications for real-world soil functioning remain uncertain. Here, we explore the drivers of realised (field) and potential (laboratory) soil net Nmin across 30 grasslands worldwide. We find that realised Nmin is largely explained by temperature of the wettest quarter, microbial biomass, clay content and bulk density. Potential Nmin only weakly correlates with realised Nmin, but contributes to explain realised net Nmin when combined with soil and climatic variables. We provide novel insights of global realised soil net Nmin and show that potential soil net Nmin data available in the literature could be parameterised with soil and climate data to better predict realised Nmin.

Breakdown of the Spectator Concept in Low-Electron-Energy Resonant Decay Processes

We suggest that low-energy electrons, released by resonant decay processes, experience substantial scattering on the electron density of excited electrons, which remain a spectator during the decay. As a result, the angular emission distribution is altered significantly. This effect is expected to be a common feature of low-energy secondary electron emission. In this Letter, we exemplify our idea by examining the spectator resonant interatomic Coulombic decay of Ne dimers. Our theoretical predictions are confirmed by a corresponding coincidence experiment.

Illness perception is significantly determined by depression and anxiety in systemic lupus erythematosus

Objectives Illness perception is a cognitive representation influencing physical and psychological functioning and adherence in patients with rheumatic disease. Studies exploring illness perception in systemic lupus erythematosus (SLE) are still scarce and none of them have investigated factors determining illness perception. We aimed to assess illness perception and to identify psychological, clinical and sociodemographic factors that might influence illness perception in SLE. Methods The study involved 80 patients with SLE (87.5% women, mean age 41.56 years). The Brief Illness Perception Questionnaire, State Trait Anxiety Inventory, Beck Depression Inventory, Pittsburgh Sleep Quality Index, Visual Analogue Scale-Pain and Fatigue Severity Scale were used. Clinical and sociodemographic data were collected via structured interview and medical files review. Results Illness perception was significantly positively correlated with anxiety, depression, sleep quality, fatigue and pain while it was not related to age, education, steroid treatment, disease duration and activity (SLEDAI) or organ damage (SLICC/ACR). Regression analysis revealed that state anxiety and depression explained 43% of illness perception variance. Cluster analysis identified three patient groups among which the middle-aged group had the most negative illness perception, the highest levels of anxiety, depression, pain and fatigue, and the poorest sleep quality. Conclusions The study has proved a significant relationship between negative illness perception and anxiety and depression. Patients reporting fatigue, poor sleep and pain might have special needs in terms of psychological intervention focused on negative illness perception and distress symptoms. Multidisciplinary care in managing SLE seems to be of great importance.

Observation of Enhanced Chiral Asymmetries in the Inner-Shell Photoionization of Uniaxially Oriented Methyloxirane Enantiomers

Most large molecules are chiral in their structure: they exist as two enantiomers, which are mirror images of each other. Whereas the rovibronic sublevels of two enantiomers are almost identical (neglecting a minuscular effect of the weak interaction), it turns out that the photoelectric effect is sensitive to the absolute configuration of the ionized enantiomer. Indeed, photoionization of randomly oriented enantiomers by left or right circularly polarized light results in a slightly different electron flux parallel or antiparallel with respect to the photon propagation direction-an effect termed photoelectron circular dichroism (PECD). Our comprehensive study demonstrates that the origin of PECD can be found in the molecular frame electron emission pattern connecting PECD to other fundamental photophysical effects such as the circular dichroism in angular distributions (CDAD). Accordingly, distinct spatial orientations of a chiral molecule enhance the PECD by a factor of about 10.

[Structural lag and room for possibilities in old age exemplified by central transitions. Initial results of a novel discipline trialogue between diaconal studies, psychology and theology]

BACKGROUND

Although the need for interdisciplinary research is generally accepted in gerontology, such interdisciplinary communication is often limited to various combinations of psychological, sociological and biomedical scientific approaches. We argue that gerontology requires a continuous examination of novel disciplinary constellations to obtain a better understanding of aging in its complexity and to further develop this scientific field in its entirety.

OBJECTIVE

The present study introduced and tested for the first time an innovative disciplinary trialogue, i.e. the combination of psychology, theology and diaconal studies. In particular, it is assumed that this combination can contribute to a more profound interpretation of the prominent concept of structural lag which is underresearched in gerontology.

MATERIAL AND METHODS

The analysis of structural lag with another overarching concept, "room for possibilities", can provide a synergy-rich interpretation category for a range of challenges connected with old age. In this respect, three major transitions were selected to shed light on these concepts and examined by means of three focus group interviews: transition to retirement, need for long-term care in the private home context and transition to nursing home life. The data were evaluated using qualitative content analysis.

RESULTS

The interdisciplinary-oriented evaluation of the interviews and the qualitative data analysis revealed the relevance of different perceptions of time in all three transitions. In addition, different dynamics in terms of the interplay of gains and losses as well as participation were found to be important for a better understanding of the three transitions. In particular, the subjective interpretation of the time remaining for living and the predetermined or self-selected time structuring of the daily routine were important factors for the perception of one's own potential. The results also underline a range of unused room for possibilities and the existence of structural lag for each transition.

CONCLUSION

By the cooperation of the participating disciplines aspects of aging and their interdependence became visible. At the same time this pilot-like disciplinary trialogue revealed the challenges in combining interdisciplinary perspectives by the combination of empirical and hermeneutical methods.

Quantitative and functional characteristics of endothelial progenitor cells in newly diagnosed hypertensive patients

Populations of peripheral blood CD34(+) cells comprise precursors of endothelial cells. These precursors are crucial to cardiovascular homeostasis. Hypertension, as one of the main risk factors for cardiovascular disease, is associated with the loss of endothelium structural integrity and its functional impairment. The aim of our study was to evaluate the subsets of endothelial precursor cells in patients with newly diagnosed arterial hypertension. Twenty-four newly diagnosed, previously untreated hypertensive patients aged 59.5 ± 12.5 years, were enrolled into the study group, whereas the control group comprised 45 healthy subjects, 55.5±10.0 years old. Endothelial progenitor cells (EPCs) were analysed by flow cytometry. The results showed that hypertensive patients were characterized by a significantly higher percentage and number of the CD34(+) cells and simultaneously less differentiated CD34(+)CD45(dim/neg)CD133(+) progenitors. The percentage and number of CD34(+)CD45(neg)VEGFR2(+) and CD34(+)CD45(neg)CD133(+)VEGFR2(+) cells were not different from the control group. Moreover, patients had a significantly lower percentage and number of the CD34(+)CD45(neg)VEGFR2(+)CXCR4(+) and CD34(+)CD45(neg)VEGFR2(+)ICAM-1(+) cells than healthy individuals. These changes were paralleled by early symptoms of nephropathy, that is, lower glomerular filtration rate (GFR) values and borderline micro albuminuria. Our results indicate that an elevation in the number of less differentiated progenitors may be a mechanism compensating for defects of migration and adhesion, present in a more differentiated subset.

[The assessment and course of development of cognitive abilities in the elderly]

BACKGROUND

The assessment of the appropriate level of development in children belongs to the standard duties of physicians in the public health system. Due to a steady increase of dementia in Germany the assessment of cognitive abilities of the elderly is becoming more and more the focus of future activities. Such an assessment of cognitive functioning reveals whether the respective person is aging normally or whether the impaired cognitive functioning is probably based on a pathological process.

OBJECTIVE

The aim of the present study is to present cognitive changes in the aged and 2 psychometric tests for the assessment of cognitive functioning: the Wechsler Adult Intelligence Scale (WAIS-IV) and the Short Cognitive Performance Test (SKT), a test for the assessment of memory impairments and impairment of attention. In addition, similarities and dissimilarities are presented.

METHODS

As part of a multi-centre study in German-speaking countries the data of 504 cognitively healthy persons between the age of 60 and 90 were tested with the WAIS-IV and the SKT.

RESULTS AND CONCLUSION

The results revealed a significant cognitive decline in the fluid and crystal intelligence depending on age. Only 2 subtests of the WAIS-IV (General Information and Block Design) showed no significant variation due to age. The SKT scores of memory and attention correlated significantly with almost all subtests of the WAIS-IV. The highest correlations were between the SKT attention score and the WAIS-IV subtests for processing speed, perceptual reasoning and working memory. The decline in cognitive abilities is mainly due to reduced capacities in speed of information processing and working memory.

Residual antimicrobial effect of chlorhexidine digluconate and octenidine dihydrochloride on reconstructed human epidermis

The objective of the present investigation was to examine the residual antimicrobial activity after a topical exposure of reconstructed human epidermis (RHE) to equimolar solutions of either chlorhexidine digluconate (CHG, 0.144% w/v) or octenidine dihydrochloride (OCT, 0.1% w/v) for 15 min. RHE-associated antiseptic agents were more effective on Staphylococcus aureus than on Pseudomonas aeruginosa. S. aureus was not detected after 24 h of contact, which demonstrated a microbicidal efficacy of greater than 5-log10 reduction. In contrast, P. aeruginosa was reduced by approximately 2 log10 at the same incubation time, which parallels the growth of the initial inoculum. This result could be interpreted either as a microbiostatic effect or as an adherence of P. aeruginosa to a low positively charged surface. Small amounts of CHG and OCT can penetrate the stratum corneum. Using these antiseptic agents, the viability of keratinocytes was reduced to 65-75% of that of the untreated RHE control following 24 h incubation in the presence of test microorganisms. With consideration of antimicrobial activity and cytotoxic effect, OCT corresponds better to a biocompatible antiseptic agent than CHG.

Neuropsychological assessment in mixed connective tissue disease: comparison with systemic lupus erythematosus

Objective: The aims of the study were to assess cognitive functions (CF) in patients with mixed connective tissue disease (MCTD) and to compare MCTD patients with systemic lupus erythematosus patients with and without neuropsychiatric manifestations (NP-SLE and non-NP-SLE, respectively) in terms of CF. Methods: Neuropsychological examination was performed in 141 patients: 30 with MCTD (24 women, 6 men), mean age: 48.07 years, 37 with non-NP-SLE (36 women, 1 man), mean age: 40.76 years and 74 with NP-SLE (68 women, 6 men), mean age: 41.97 years. Neuropsychological tests and structured interview were used. Emotional state was assessed by Hospital Anxiety and Depression Scale and clinical review. Results: We observed cognitive impairment in six MCTD patients (20%); in one (3%) the impairment was severe. MCTD patients achieved significantly higher results in seven out of 11 tests compared with patients with NP-SLE. MCTD and non-NP-SLE patients did not differ significantly. The differences were irrespective of premorbid IQ, education, disease duration and steroid treatment. Conclusions: In the majority of MCTD patients, CF were not impaired and severe impairment was unusual. Cognitive functioning was most disturbed in NP-SLE. The cognitive deficits observed in connective tissue diseases can be connected with nervous system involvement.

Neuropsychological assessment in systemic lupus erythematosus patients: clinical usefulness of first-choice diagnostic tests in detecting cognitive impairment and preliminary diagnosis of neuropsychiatric lupus

OBJECTIVES

To evaluate the usefulness of neuropsychological tests in order to distinguish the first-choice methods useful in quick detection of cognitive impairment in SLE and preliminary diagnosis of neuropsychiatric manifestation. Study aimed at assessment of the prevalence and severity of cognitive deficits in SLE patients and comparison between SLE patients with neuropsychiatric manifestations (NP-SLE) and without ones (non-NP-SLE).

METHODS

93 out of 104 SLE patients, 57 with NP-SLE and 36 with non-NP-SLE underwent comprehensive neuropsychological examination. Tailor-made structured interview for neuropsychological assessment in SLE (SISLE) was used. Patients' emotional state was assessed by clinical interview and HADS.

RESULTS

Cognitive dysfunction was identified in 57% of SLE patients, 48.4% in 1-3 tests, 8.6% (8 patients) in 4 or more tests (severe decline). Among impaired patients 15% had severe decline. In NP-SLE group 63.2% were impaired vs. 47.2% in non-NP-SLE group. All 8 patients with severe decline were NP-SLE. The dysfunction was irrespective of premorbid intellectual level, age, education, disease duration and steroid treatment. In NP-SLE significantly lower scores were observed in 8 tests (10 parameters).

CONCLUSIONS

Cognitive dysfunction is frequent in SLE patients. The majority of patients has mild deficits, but severe decline is also observed. The dysfunction is more frequent and more pronounced in NP-SLE. The study distinguished 8-test-first-choicebattery useful in detecting cognitive impairment in SLE and in case of severe decline - in preliminary differentiating NP-SLE and non-NP-SLE. Structured interview for psychological/neuropsychological examination of SLE patients is a useful and required tool for a standard patients' assessment.

Melting of peridotite to 140 gigapascals

Interrogating physical processes that occur within the lowermost mantle is a key to understanding Earth's evolution and present-day inner composition. Among such processes, partial melting has been proposed to explain mantle regions with ultralow seismic velocities near the core-mantle boundary, but experimental validation at the appropriate temperature and pressure regimes remains challenging. Using laser-heated diamond anvil cells, we constructed the solidus curve of a natural fertile peridotite between 36 and 140 gigapascals. Melting at core-mantle boundary pressures occurs at 4180 ± 150 kelvin, which is a value that matches estimated mantle geotherms. Molten regions may therefore exist at the base of the present-day mantle. Melting phase relations and element partitioning data also show that these liquids could host many incompatible elements at the base of the mantle.

Standardized comparison of antiseptic efficacy of triclosan, PVP-iodine, octenidine dihydrochloride, polyhexanide and chlorhexidine digluconate

BACKGROUND

This study presents a comparative investigation of the antimicrobial efficacy of the antiseptics PVP-iodine, triclosan, chlorhexidine, octenidine and polyhexanide used for pre-surgical antisepsis and antiseptic treatment of skin, wounds and mucous membranes based on internationally accepted standards.

METHODS

MICs and MBCs were determined in accordance with DIN 58940-7 and 58940-8 using Staphylococcus aureus (including methicillin-resistant Staphylococcus aureus), Enterococcus faecalis (including vancomycin-resistant Enterococcus), Streptococcus pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Clostridium perfringens, Haemophilus influenzae and Candida albicans. The microbicidal efficacy was determined in accordance with DIN EN 1040 and 1275 using S. aureus, P. aeruginosa and C. albicans.

RESULTS

For chlorhexidine, octenidine and polyhexanide, MIC(48) and MBC(24) ranged from 16 to 32 mg/L. Maximum values for triclosan ranged from 256 to 512 mg/L, with an efficacy gap against P. aeruginosa, while the maximum values of PVP-iodine were 1024 mg/L, with a gap against S. pneumoniae. Comparing the minimal effective concentrations, octenidine was most effective. After 1 min, only octenidine and PVP-iodine fulfil the requirements for antiseptics.

CONCLUSIONS

Tests under standardized and harmonized conditions help to choose the most efficacious agent. When a prolonged contact time is feasible, ranking of agents would be polyhexanide = octenidine > chlorhexidine > triclosan > PVP-iodine. This is consistent with the recommendations for antisepsis of acute wounds. Polyhexanide seems to be preferable for chronic wounds due to its higher tolerability. If an immediate effect is required, ranking would be octenidine = PVP-iodine>> polyhexanide > chlorhexidine > triclosan.

Octenidine dihydrochloride, a modern antiseptic for skin, mucous membranes and wounds

Octenidine dihydrochloride (octenidine) was introduced for skin, mucous membrane and wound antisepsis more than 20 years ago. Until now, a wealth of knowledge has been gained, including in vitro and animal studies on efficacy, tolerance, safety and clinical experience both from case reports and prospective controlled trials. Nowadays, octenidine is an established antiseptic in a large field of applications and represents an alternative to older substances such as chlorhexidine, polyvidone-iodine or triclosan. The review is based on the current literature and unpublished original data as well.

Topical antiseptics as an alternative in the treatment of acute vulvovaginal candidosis

The aim of this prospective, multicenter, randomized, case-control study was to investigate the efficacy of a nonspecific mucosal antiseptic (octenidine dihydrochloride, phenoxyethanol) with proven antifungal effects, in patients with acute symptomatic vaginal candidosis, in comparison with a specific topical antifungal agent (clotrimazole), particularly in respect to non-Candida albicans yeasts. A total of 491 patients from 29 gynecological practices, who had new clinical vaginal mycosis, not treated with antifungal agents in the last 12 months, were included in the study. The diagnosis in each case was confirmed by microscopy or positive culture. The majority of the vaginal mycoses were infections with C. albicans (72%). In 28% of patients a non- Candida species (mainly C. glabrata) contributed to the infection. Except for vaginal discharge, the success of treatment was between 71% and 91% for both clinical and subjective parameters. The control preparation was significantly better than the treatment in the test group. Mycological cure rate on the basis of cultures was 78% in the test group and 87% in the control group. These results were also significantly different. The relatively high proportion of C. glabrata isolates in this study tended to be more successfully treated by the antiseptic (to 72%) than by the administration of clotrimazole (59%). Even though therapeutic success with clotrimazole was overall significantly better than with the test preparation, the success of treatment with the antiseptic used was within the range between 70% and 90% described for topical antifungal agents. Both the good efficacy of the topical antiseptic and the increased prevalence of non-Candida albicans species causing vaginal infections mean that the use of an antiseptic may be considered a suitable alternative therapeutic concept to an appropriate topical antifungal agent in the treatment of acute vaginal candidosis.

Use of 2% 2-phenoxyethanol and 0.1% octenidine as antiseptic in premature newborn infants of 23-26 weeks gestation

In preterm newborn infants, topical iodine-containing antiseptics disturb thyroid hormone regulation while alcohol-based disinfectants may cause local burns. We therefore investigated the use of an aqueous solution containing 0.1% octenidine and 2% 2-phenoxyethanol for skin disinfection during the first seven days of life in premature newborns with a gestational age <27 weeks who were consecutively admitted to our level III neonatal intensive care unit between November 1, 2000 and December 31, 2001 (N=24). In boys. (N=13) the renal excretion of absorbed 2-phenoxyethanol and its metabolite 2-phenoxyacetic acid was quantitated by high-pressure liquid chromatography. In the most immature newborn (gestational age 23 6/7 weeks), a transient erythematous reaction was observed following application of the octenidine/phenoxyethanol solution prior to umbilical vessel catheterization. No other local reactions were observed. The urinary concentration of 2-phenoxyethanol was <2 ppm in all samples, while urinary 2-phenoxyacetic acid concentrations reached 5-95 ppm (median 24 ppm). One infant had a culture-proven septicaemia (Bacillus species) during the first seven days of life. We conclude that, in contrast to alcohol-based antiseptics, an aqueous solution of 0.1% octenidine and 2-phenoxyethanol does not cause major skin damage in premature newborn infants <27 weeks' gestation. 2-Phenoxyethanol is readily absorbed by the newborn's skin but apparently undergoes extensive oxidative metabolization to 2-phenoxyacetic acid.

Characterization of 15 selected coccal bacteria isolated from Antarctic rock and soil samples from the McMurdo-Dry Valleys (South-Victoria Land)

Approximately 1500 cultures of microorganisms were isolated from rocks and soils of the Ross Desert (McMurdo-Dry Valleys). From these, 15 coccoid strains were chosen for more detailed investigation. They were characterized by morphological, physiological and chemotaxonomical properties. All isolates were Gram-positive, catalase-positive and nonmotile. Six strains showed red pigmentation and could be identified as members of the genera Micrococcus (M. roseus, M. agilis) or Deinococcus. In spite of their coccoid morphology, the remaining nine strains had to be associated with coryneform bacteria (Arthrobacter, Brevibacterium), because of their cell wall composition and G+C ratios. Most of the strains were psychrotrophic, but one strain was even obligately psychrophilic, with a temperature maximum below 20 degrees C. Red cocci had in vitro pH optima above 9.0 although they generally originated from acid samples. Most isolates showed a preference for sugar alcohols and organic acids, compounds which are commonly known to be released by lichens, molds and algae, the other components of the cryptoendolithic ecosystem. These properties indicate that our strains are autochthonous members of the natural Antarctic microbial population.

IL-8 concentration in coronary sinus blood during early coronary reperfusion after ischemic arrest

OBJECTIVE

Activation of the inflammatory response is an important factor contributing to complications of cardiopulmonary bypass. Increased level of proinflammatory cytokine - IL-8 has been reported during coronary artery bypass grafting (CABG) operations with the use of cardiopulmonary bypass. The aim of this study was to find out whether the heart is the main source of IL-8 during early coronary reperfusion.

METHODS

IL-8 concentration in coronary sinus before clamping and 5, 10, and 15 min after declamping of the aorta as well as in radial artery blood before clamping and 10 min after declamping of the aorta, was assessed in 30 patients undergoing CABG surgery.

RESULTS

We observed increase in IL-8 concentration in coronary sinus blood after declamping of the aorta, however no difference between coronary sinus and arterial blood concentration was noted. The median value of IL-8 concentration in coronary sinus blood was 1.85 pg/ml before ischemia and 15.4, 20.3, and 29.3 pg/ml in 5, 10 and 15 min after aortic declamping, respectively. Our additional finding was that there was a negative correlation between IL-8 level and hemoglobin saturation with oxygen in coronary sinus blood 10 min after coronary reperfusion.

CONCLUSIONS

We conclude that the heart is not the main source of IL-8 in early coronary reperfusion, although coronary reperfusion induces its release.

Application of intraoperative thermography in coronary artery bypass grafting without extracorporeal circulation - clinical report

BACKGROUND

The development of low-invasive cardiosurgical techniques has contributed to an increase of the number of revascularization procedures performed on beating heart. The report presents the changes observed intraoperatively in thermographic images of the heart obtained during surgical revascularization performed without extracorporeal circulation.

MATERIAL AND METHODS

In two patients with coronary heart disease, subjected to coronary artery bypass grafting performed without extracorporeal circulation, the images acquired over the operation area were recorded intraoperatively using a thermovision camera (Agema Thermovision SW/TE 900 system).

RESULTS

On the basis of thermographic images, the area of lowered temperature corresponding to the region of myocardium with impaired blood flow supplied by the descending anterior coronary artery branch was determined. A rapid temperature increase to the baseline values was observed soon after removing the ligatures from the descending anterior coronary artery and left internal mammary artery used as a bypass.

CONCLUSIONS

Recording thermographic heart images allows to observe restricted areas of perfusion disturbances, which take place during procedures performed on beating heart.

Atrial fibrillation after coronary artery bypass grafting: does the type of procedure influence the early postoperative incidence?

OBJECTIVE

Atrial fibrillation (AF), the common postoperative complication, has been observed after coronary artery bypass grafting (CABG) in 7--40% of patients. Cardiopulmonary bypass (CPB), eliminated in off-pump operations (OPCABG) may decrease the incidence of AF, whereas the combination of CABG with heart valve replacement may result in more frequent postoperative atrial fibrillation. The aim of our study was to compare the early postoperative AF incidence rate during ICU stay in three groups of patients: after CABG, OPCABG, and CABG combined with valve replacement.

MATERIAL AND METHODS

A prospective study of 906 consecutive patients was carried out between January 1999 and January 2000. Clinical profile of 906 patients, including factors having potential influence on postoperative AF did not showed any significant differences between the groups. The presence of arrhythmia history was the reason of excluding 85 patients from the statistical analysis. The observation was performed in each case during ICU-stay, using a HP system for continuous automated arrhythmia analysis. Early postoperative incidence of AF was recorded and compared between three groups of patients: 650 after conventional CABG, 118 after OPCABG, and 53 after CABG combined with valve replacement. Chi-square and a Mann--Whitney tests, Statistica 5.0 PL were used for the statistical analysis.

RESULTS

Atrial fibrillation occurred during the postoperative ICU stay in 9.8% of patients after CABG, in 10.2% after OPCABG, and in 21% after CABG combined with valve replacement. There was no significant difference between CABG and OPCABG groups (P=0.965). The confidence interval of the odds ratio ranges from 0.5 to 1.85. Consequently, an increased risk would be possible for both methods. We observed a statistically significant increase of the early postoperative atrial fibrillation incidence rate in patients after CABG combined with valve replacement, when compared with both CABG + OPCABG groups (P=0.005).

CONCLUSIONS

(1) Atrial fibrillation is a common postoperative complication after myocardial revascularization procedures which prolongs ICU stay. (2) The study did not show that the incidence of postoperative AF is influenced by the technique of coronary artery bypass grafting: with or without CPB. (3) The prevalence of postoperative AF increase when CABG is combined with valve replacement.

Administration of clemastine--H1 histamine receptor blocker in the prevention of haemodynamic disorders after protamine sulfate administration in patients subjected to coronary artery bypass grafting in extracorporeal circulation

INTRODUCTION

Adverse effects of protamine administration after CPB: fall in arterial blood pressure and pulmonary hypertension are still a source of problems. CPB and protamine administration are both accompanied by increased histamine levels in blood. The aim of this study was to examine if clemastine can accelerate the normalisation of arterial blood pressure during the protamine administration after CPB during CABG operations.

MATERIAL AND METHODS

Fifty three patients subjected to CABG operations were studied. Control group (n = 27) did not receive clemastine, Clemastine group (n = 26) received 2 mg i.v. clemastine, before CPB. After CPB were completed, patients were given protamine (heparin to protamine ratio--1:1.5) within 7 minutes, through peripheral vein. Changes in arterial blood pressure from the beginning of protamine administration to 2.5, 5, 7.5, 10, 15, and 30 minutes thereafter, as well as heart rate, CVP, doses of inotropic drugs and vasodilators were compared between the groups.

RESULTS

No difference in heart rate, CVP, doses of inotropic drugs and vasodilators between the group was noted. An increase in arterial blood pressure 5, 7.5, 10, and 15 minutes after the beginning of the protamine administration were greater in clemastine group than in control group. Groups were comparable with regard to surgical procedures and doses of anaesthetic drugs. It is now known that protamine exerts a negative effect on cardiac contractility either through a decrease in coronary perfusion pressure (vasodilatation), or through a direct toxic effect on cardiac muscle. The administration of clemastine before CPB can reduce peripheral vasodilatation and capillary leak related to histamine release during CPB. In the clemastine group, faster increase in arterial blood pressure toward a physiologic range was observed. We conclude that administration of clemastine is connected with the normalization of ABP during and after protamine reversal of heparin coagulation during CABG operations.

Atrial fibrillation after coronary artery bypass grafting without cardiopulmonary bypass

OBJECTIVE

Atrial fibrillation is the most common complication after heart surgery. It rarely has a fatal outcome but causes patient instability, prolongs hospital stay, or even is the reason for perioperative infarction. Although conventional coronary artery bypass grafting (CABG) with cardiopulmonary bypass has excellent short-term and long-term results, the number of coronary operations on a beating heart without cardiopulmonary bypass is still growing. To reduce surgical trauma, off-pump coronary artery bypass grafting via sternotomy (OPCABG) or minimally invasive direct vision coronary artery bypass grafting (MIDCABG) via small thoracotomy are performed. The aim of this study was to estimate the frequency of atrial fibrillation in patients after myocardial revascularization without cardiopulmonary bypass.

METHODS

A retrospective analysis of 48 patients undergoing myocardial revascularization without cardiopulmonary bypass was performed. Twenty-four patients underwent OPCABG and 24 were operated using the MIDCABG technique. The incidence of cardiac arrhythmias was analyzed since operation to the fourth postoperative day. Each patient had continuous ECG monitoring with option of arrhythmia analysis during ICU stay. After discharge from ICU 24-h ECG monitor studies were carried out. Surface 12-lead ECG was accomplished once a day, and additionally each time symptoms of cardiac arrhythmia occurred. Risk factors of atrial fibrillation were estimated.

RESULTS

Atrial fibrillation occurred in 25% of patients after MIDCABG, in 29% after OPCABG, and in 18% after CABG with cardiopulmonary bypass. This difference has no statistical significance. Risk factors and incidence of postoperative complications were comparable in all groups.

CONCLUSIONS

Atrial fibrillation is a common complication after procedures of myocardial revascularization, performed with or without cardiopulmonary bypass. The occurrence is not dependent on the type of operation.

[Less invasive coronary artery bypass grafting]

Myocardial revascularization had its beginnings in the early 1900s with extracardiac operations, such as sympathetic denervation and thyroid ablation. Since than it evolved to saphenous vein- and mammary artery-coronary artery bypass grafting (CABG) on the beating heart in the 1960s and after 1975 with the use of cardiopulmonary bypass (CPB) and cardioplegic arrest. Although excellent short-term and long-term results have been obtained with conventional CABG on cardiopulmonary bypass, there is still significant mortality and morbidity associated with the procedure, especially in the higher risk patients. To reduce surgical trauma off-pump coronary artery bypass grafting (OPCABG) and minimally invasive direct vision coronary artery bypass grafting (MIDCABG) are performed. Totally endoscopic operations are still in experimental stage. In the article optional less invasive surgical techniques are described.

Eradication of MRSA from carriers by means of whole-body washing with an antiseptic in combination with mupirocin nasal ointment

Patients who are infected or colonised by MRSA should be isolated. However, isolation is very costly in terms of time and work. In order to shorten the period of isolation, attempts are being made to eradicate this organism from patients by means of whole-body washing in addition to nasal mupirocin treatment. The effectiveness of such washes has not yet been adequately confirmed by studies. From September 1997 to August 1998, therefore, in a clinical trial of MRSA eradication, 28 patients were washed for a period of five days with a 1:1 diluted preparation based on octenidine dihydrochloride. At the same time, the nose was treated with mupirocin. Before washing was begun, on day 4 during washing and on days 1, 4 and 7 after washing was completed, smears were taken from each patient from the nose, pharynx, forehead hairline, groin, axilla and wounds, and in the case of women from the sub-mammary area. Elimination of the MRSA was achieved in 21 out of 28 cases; in four cases the washing was discontinued on account of skin redness, in three cases no elimination could be achieved during the control period. In order to ensure the success of eradication and to minimise skin reactions due to the washing, the wash procedure must be standardised, and decontamination controlled microbiologically. The study confirms that MRSA can be eradicated by means of washing with an antiseptic combined with mupirocin treatment.

Stroke volume variability--cardiovascular response to orthostatic maneuver in patients with coronary artery diseases

The dynamics of cardiovascular responses to postural stress have not been fully recognized. To determine whether coronary artery bypass grafting (CABG) has any effect on stroke volume variability (SVV), the power spectrum components of SVV were measured in 60 patients before and at 6 weeks after CABG. Stroke volume was assessed by means of the thoracic bioimpedance method. The thoracic impedance cardiogram and ECG were recorded in the supine and standing positions with controlled breathing rate (0.25 Hz) during 10-minute periods. The analysis of SVV was done by means of the autoregressive method. The total power, the power in the low-frequency band LFSV (0.05-0.15 Hz), the power in the high-frequency band HFSV (0.15-0.5 Hz), and the LFSV/HFSV ratio were analyzed. Before CABG, we did not notice any significant changes in the stroke volume spectral power indices. After CABG, all spectral indices were significantly decreased in the standing position.

Heart rate power spectral analysis in patients before and 6 weeks after coronary artery bypass grafting

Decreased cardiac vagal activity is a known risk factor in coronary artery disease. The aim of our study was to determine the effect of coronary artery bypass grafting (CABG) on heart rate variability (HRV) before and 6 weeks after CABG. The study group consisted of 34 patients (4 women, 30 men, mean age 56 +/- 9 years). ECGs were recorded in 10 minutes periods in both supine and standing position with controlled breathing rate (0.25Hz). The analysis of HRV power spectrum was done by means of fast Fourier transformation. The total spectral power (TPS), power in very low frequency band (VLF: < 0.05 Hz), low frequency band (LF:0.05-0.15Hz), high frequency band (HF:0.15-0.5Hz), LF/HF ratio and percentage fraction of total power in these frequency bands (%VLF, %LF, %HF) were analysed. Significant attenuation of all spectral components of HRV were found during orthostatic load before CABG (p < 0.05). TPS, VLF, LF, %HF decreased in standing position to about half of their level in supine position, HF decreased to as little as one fourth, while LF/HF ratio and %LF increased significantly (p < 0.05). After the CABG these changes were not significant. We have found significant increase of HF (p < 0.05) and %HF (p < 0.01) in standing position after the CABG. The results suggest that CABG causes an improvement in cardiac vagal activity especially in standing position.