Intracranial complications of sinogenic and otogenic infections in children: an ESPN survey on their occurrence in the pre-COVID and post-COVID era.

BACKGROUND: COVID-19 pandemic is thought to have changed the epidemiology of some pediatric neurosurgical disease: among them are the intracranial complications of sinusitis and otitis (ICSO). According to some studies on a limited number of cases, both streptococci-related sinusitis and ICSO would have increased immediately after the pandemic, although the reason is not clear yet (seasonal changes versus pandemic-related effects). The goal of the present survey of the European Society for Pediatric Neurosurgery (ESPN) was to collect a large number of cases from different European countries encompassing the pre-COVID (2017-2019), COVID (2020-2021), and post-COVID period (2022-June 2023) looking for possible epidemiological and/or clinical changes. MATERIAL AND METHODS: An English language questionnaire was sent to ESPN members about year of the event, patient's age and gender, presence of immune-deficit or other favoring risk factors, COVID infection, signs and symptoms at onset, site of primary infection, type of intracranial complication, identified germ, type and number of surgical operations, type and duration of medical treatment, clinical and radiological outcome, duration of the follow-up. RESULTS: Two hundred fifty-four cases were collected by 30 centers coming from 14 different European countries. There was a statistically significant difference between the post-COVID period (129 children, 86 cases/year, 50.7% of the whole series) and the COVID (40 children, 20 cases/year, 15.7%) or the pre-COVID period (85 children, 28.3 cases/year, 33.5%). Other significant differences concerned the presence of predisposing factors/concurrent diseases (higher in the pre-COVID period) and previous COVID infection (higher in the post-COVID period). No relevant differences occurred as far as demographic, microbiological, clinical, radiological, outcome, morbidity, and mortality data were concerned. Paranasal sinuses and middle ear/mastoid were the most involved primary site of infection (71% and 27%, respectively), while extradural or subdural empyema and brain abscess were the most common ICSO (73% and 17%, respectively). Surgery was required in 95% of cases (neurosurgical and ENT procedure in 71% and 62% of cases, respectively) while antibiotics in 99% of cases. After a 12.4-month follow-up, a full clinical and radiological recovery was obtained in 85% and 84% of cases, respectively. The mortality rate was 2.7%. CONCLUSIONS: These results suggest that the occurrence of ICSO was significantly increased after the pandemic. Such an increase seems to be related to the indirect effects of the pandemic (e.g., immunity debt) rather than to a direct effect of COVID infection or to seasonal fluctuations. ICSO remain challenging diseases but the pandemic did not affect the management strategies nor their prognosis. The epidemiological change of sinusitis/otitis and ICSO should alert about the appropriate follow-up of children with sinusitis/otitis.

Patterns, predictors and prognostic relevance of high-grade hematotoxicity after temozolomide or temozolomide-lomustine in the CeTeG/NOA-09 trial.

PURPOSE: In the randomized phase III trial CeTeG/NOA-09, temozolomide (TMZ)/lomustine (CCNU) combination therapy was superior to TMZ in newly diagnosed MGMT methylated glioblastoma, albeit reporting more frequent hematotoxicity. Here, we analyze high grade hematotoxicity and its prognostic relevance in the trial population. METHODS: Descriptive and comparative analysis of hematotoxicity adverse events ≥ grade 3 (HAE) according to the Common Terminology of Clinical Adverse Events, version 4.0 was performed. The association of HAE with survival was assessed in a landmark analysis. Logistic regression analysis was performed to predict HAE during the concomitant phase of chemotherapy. RESULTS: HAE occurred in 36.4% and 28.6% of patients under CCNU/TMZ and TMZ treatment, respectively. The median onset of the first HAE was during concomitant chemotherapy (i.e. first CCNU/TMZ course or daily TMZ therapy), and 42.9% of patients with HAE receiving further courses experienced repeat HAE. Median HAE duration was similar between treatment arms (CCNU/TMZ 11.5; TMZ 13 days). Chemotherapy was more often discontinued due to HAE in CCNU/TMZ than in TMZ (19.7 vs. 6.3%, p = 0.036). The occurrence of HAE was not associated with survival differences (p = 0.76). Regression analysis confirmed older age (OR 1.08) and female sex (OR 2.47), but not treatment arm, as predictors of HAE. CONCLUSION: Older age and female sex are associated with higher incidence of HAE. Although occurrence of HAE was not associated with shorter survival, reliable prediction of patients at risk might be beneficial to allow optimal management of therapy and allocation of supportive measures. TRIAL REGISTRATION: NCT01149109.

Integration of radiation oncology teaching in medical studies by German medical faculties due to the new licensing regulations : An overview and recommendations of the consortium academic radiation oncology of the German Society for Radiation Oncology (DEGRO).

The new Medical Licensing Regulations 2025 (Ärztliche Approbationsordnung, ÄApprO) will soon be passed by the Federal Council (Bundesrat) and will be implemented step by step by the individual faculties in the coming months. The further development of medical studies essentially involves an orientation from fact-based to competence-based learning and focuses on practical, longitudinal and interdisciplinary training. Radiation oncology and radiation therapy are important components of therapeutic oncology and are of great importance for public health, both clinically and epidemiologically, and therefore should be given appropriate attention in medical education. This report is based on a recent survey on the current state of radiation therapy teaching at university hospitals in Germany as well as the contents of the National Competence Based Learning Objectives Catalogue for Medicine 2.0 (Nationaler Kompetenzbasierter Lernzielkatalog Medizin 2.0, NKLM) and the closely related Subject Catalogue (Gegenstandskatalog, GK) of the Institute for Medical and Pharmaceutical Examination Questions (Institut für Medizinische und Pharmazeutische Prüfungsfragen, IMPP). The current recommendations of the German Society for Radiation Oncology (Deutsche Gesellschaft für Radioonkologie, DEGRO) regarding topics, scope and rationale for the establishment of radiation oncology teaching at the respective faculties are also included.

The Tutor of Resilience Program with Children Who Have Experienced Maltreatment: Mothers' Involvement Matters.

Resilience is a dynamic process involving the presence and interaction of personal and environmental factors that modify the impact of adversity. Resilience-building interventions are therefore important for improving trauma-related outcomes in children and caregivers exposed to adversity. This study examines the impact of the Tutor of Resilience (TOR) program on beneficiaries' trauma-related symptoms and on mother-child interactions in a group of children exposed to maltreatment (N = 186; mean age = 11.95; SD = 2.50). Assessments were completed at baseline and post-intervention. RM-ANOVAs indicated significant improvements for most trauma symptoms (anxiety, anger, post-traumatic stress, and disassociation, but not depression) in the intervention group relative to a control group (N = 88; mean age = 10.76; SD = 2.57), and indicated further improvements to anxiety and dissociation for the intervention group when mothers were involved. Mother-child interactions also improved over time, as did their overall trauma symptoms and distress. Findings support the effectiveness of the ToR, especially when involving mothers.

The National Institute of Health and the Italian Poison Centers Network: results of a collaborative study for the surveillance of exposures to chemicals.

Background: The Public Health Surveillance Systems are essential to improve and protect public health, as highlighted by the World Health Organization. According with this consideration, a systematic collaboration between the National Institute of Health and the Poison Centers of Northern, Central and Southern Italy was established. Its aim was to improve the national network for the surveillance of dangerous exposures to chemicals. The developed network provided harmonized data essential for evidence-based interventions and significantly ameliorated the data flow between the Poison Centers and the Central Health Institutions. Methods: The improvement of the system was obtained through several actions, such as the development of the "Online Surveillance Card" for the detection of sentinel events in real time and the harmonization of the data collection flow, including the product categorization according to the European Product Categorization System. Data analysis was carried out by Microsoft's IBM SPSS Statistics version 26, Access and Excel. Results: Important information was obtained, regarding also exposures to chemicals and their management in pediatric populations. The surveillance network was proved effective not only under "normal" conditions but also to promptly monitor changes during exceptional health emergencies, such as the COVID-19 pandemic. During the 2020 lockdown the surveillance system registered a significant increase in the frequency of exposures to disinfectants (p-value=0.002), an evidence that highlighted the need of tailored intervention. Conclusions: This Italian Project model proves to be reliable and suitable to be transferred to other European countries, in order to realize an European Poison Centers' Network, able to overcome unsolved health problems and to globally improve the "evidence-based" prevention of exposures to chemicals.

Prognostic impact of gross tumor volume during radical radiochemotherapy of locally advanced non-small cell lung cancer-results from the NCT03055715 multicenter cohort study of the Young DEGRO Trial Group.

BACKGROUND: In radical radiochemotherapy (RCT) of inoperable non-small-cell lung cancer (NSCLC) typical prognostic factors include T- and N-stage, while there are still conflicting data on the prognostic relevance of gross tumor volume (GTV) and particularly its changes during RCT. The NCT03055715 study of the Young DEGRO working group of the German Society of Radiation Oncology (DEGRO) evaluated the prognostic impact of GTV and its changes during RCT. METHODS: A total of 21 university centers for radiation oncology from five different European countries (Germany, Switzerland, Spain, Belgium, and Austria) participated in the study which evaluated n = 347 patients with confirmed (biopsy) inoperable NSCLC in UICC stage III A/B who received radical curative-intent RCT between 2010 and 2013. Patient and disease data were collected anonymously via electronic case report forms and entered into the multi-institutional RadPlanBio platform for central data analysis. GTV before RCT (initial planning CT, GTV1) and at 40-50 Gy (re-planning CT for radiation boost, GTV2) was delineated. Absolute GTV before/during RCT and relative GTV changes were correlated with overall survival as the primary endpoint. Hazard ratios (HR) of survival analysis were estimated by means of adjusted Cox regression models. RESULTS: GTV1 was found to have a mean of 154.4 ml (95%CI: 1.5-877) and GTV2 of 106.2 ml (95% CI: 0.5-589.5), resulting in an estimated reduction of 48.2 ml (p < 0.001). Median overall survival (OS) was 18.8 months with a median of 22.1, 20.9, and 12.6 months for patients with high, intermediate, and low GTV before RT. Considering all patients, in one survival model of overall mortality, GTV2 (2.75 (1.12-6.75, p = 0.03) was found to be a stronger survival predictor than GTV1 (1.34 (0.9-2, p > 0.05). In patients with available data on both GTV1 and GTV2, absolute GTV1 before RT was not significantly associated with survival (HR 0-69, 0.32-1.49, p > 0.05) but GTV2 significantly predicted OS in a model adjusted for age, T stage, and chemotherapy, with an HR of 3.7 (1.01-13.53, p = 0.04) per 300 ml. The absolute decrease from GTV1 to GTV2 was correlated to survival, where every decrease by 50 ml reduced the HR by 0.8 (CI 0.64-0.99, p = 0.04). There was no evidence for a survival effect of the relative change between GTV1 and GTV2. CONCLUSION: Our results indicate that independently of T stage, the re-planning GTV during RCT is a significant and superior survival predictor compared to baseline GTV before RT. Patients with a high absolute (rather than relative) change in GTV during RT show a superior survival outcome after RCT.

Olive leaf extract counteracts epithelial to mesenchymal transition process induced by peritoneal dialysis, through the inhibition of TGFß1 signaling.

The mesothelial cells (MCs) play an important role in the morpho-functional alterations of the peritoneal membrane (PM) undergoing peritoneal dialysis (PD). MCs, through the epithelial-mesenchymal transition process (EMT), progressively acquire a myofibroblast-like phenotype, promoting peritoneal fibrosis (PF) and failure of peritoneal membrane function. Transforming growth factor ß1 (TGFß1), through canonical and non-canonical pathways, promotes the epithelial-mesenchymal transition (EMT) process leading to PF. To investigate the therapeutic potential of an olive leaf extract (OLE) on preserving peritoneal membrane function, we evaluated the effect of OLE on the TGFß1-induced EMT in mesothelial cells, Met5A, and elucidated the underlying molecular mechanisms. As assessed by changes in the expression of epithelial, mesenchymal, and fibrotic cell markers (such as E-cadherin, N-cadherin, α-SMA, fibronectin, vimentin), levels of matrix metalloproteinases (MMP2 and MMP9), and cell migration, OLE inhibited the TGFß1-induced EMT. Importantly, the beneficial effect of OLE was mediated by reduction of the TGFß1-induced activation of Smad2/3 signaling and the mitigation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) phosphorylation. Smad/non-Smad signaling pathways, activated by TGFß1, both reduce expression of epithelial marker E-cadherin which has a crucial role in EMT initiation. Interestingly, we observed that in presence of OLE activity of the E-cadherin, promoter was increased and concomitantly OLE reduced the nuclear content of its co-repressor SNAIL. Our results suggest the potential therapeutic of OLE to counteract fibrotic process in peritoneal dialysis patients.

Brain morphometry of preschool age children affected by autism spectrum disorder: Correlation with clinical findings.

The aim of our study was to use a combined imaging and clinical approach to identify possible patterns of clinical and imaging findings in a cohort of preschool age autism spectrum disorder (ASD) patients. In order to identify imaging patterns that could be related to specific clinical features, a selected group of ASD patients (age range 3-6 years) without dysmorphic features, epilepsy or other major neurological signs, malformations or other lesions at MRI was subjected to brain volumetric analysis using semiautomatic brain segmentation. An age-matched group of typically developing children was subjected to the same analysis. Our results were consistent with previous literature: Total gray matter volume, total cortical gray matter volume and amygdalar volumes were significantly greater in the ASD group than the control group. When we divided the study group into subgroups on the basis of clinical findings such as high- or low-functioning, or verbal and nonverbal, the only significant difference between verbal and nonverbal subjects was in cerebellar hemispheric size. In conclusions, our results confirm that newer brain MRI techniques using semiautomatic brain segmentation can provide information useful for defining the differences between ASD patients and controls, particularly if they form part of an integrated approach between MRI and cognitive-behavioral and genetic data. Clin. Anat. 32:143-150, 2019. © 2018 Wiley Periodicals, Inc. HIGHLIGHTS: Combined imaging and clinical approach in autism spectrum disorders Semiautomatic brain segmentation in a selected preschool age ASD group Reduced total cerebellar white matter volume in non-verbal ASD patients.

Synthesis of phenylpyrimidinones as guanylyl cyclase C inhibitors.

Diarrhea is one of the most important causes of mortality in the developing world, being responsible for 2.5 million deaths each year. Many of these deaths are caused by enterotoxigenic strains of bacteria, like Escherichia coli, that produce enterotoxins that cause acute watery diarrhea, commonly defined as secretory diarrhea. Studies on symptomatic patients indicate a high prevalence of enterotoxigenic E. coli strains producing the heat-stable toxin, STa. STa is a small, cysteine-rich peptide that binds to the extracellular receptor domain of guanylyl cyclase C (GCC), located at the luminal membrane of intestinal epithelial cells. GCC and its endogenous peptide ligands, guanylin and uroguanylin, play a key role in balancing water absorption and hydration of the intestinal lumen, as exemplified by the finding that loss of GCC function causes severe dehydration of the intestinal lumen, culminating in intestinal obstruction. From a mechanistic viewpoint, reduction of GCC activity offers an efficient approach to limit enterotoxigenic E. coli- provoked secretory diarrhea. Inhibition of GCC-mediated cGMP production would not only reduce anion secretion, but would also restore NHE3 activity, resulting in a comprehensive antidiarrheal action. In the present study, two novel phenylpyrimidinone derivatives were simultaneously synthesized and tested for their ability to block STa-induced CFTR activity in T84 cells.

Unresolved Gamma-Ray Sky through its Angular Power Spectrum.

The gamma-ray sky has been observed with unprecedented accuracy in the last decade by the Fermi -large area telescope (LAT), allowing us to resolve and understand the high-energy Universe. The nature of the remaining unresolved emission [unresolved gamma-ray background (UGRB)] below the LAT source detection threshold can be uncovered by characterizing the amplitude and angular scale of the UGRB fluctuation field. This Letter presents a measurement of the UGRB autocorrelation angular power spectrum based on eight years of Fermi-LAT Pass 8 data products. The analysis is designed to be robust against contamination from resolved sources and noise systematics. The sensitivity to subthreshold sources is greatly enhanced with respect to previous measurements. We find evidence (with ∼3.7σ significance) that the scenario in which two classes of sources contribute to the UGRB signal is favored over a single class. A double power law with exponential cutoff can explain the anisotropy energy spectrum well, with photon indices of the two populations being 2.55±0.23 and 1.86±0.15.

Search for Cosmic-Ray Electron and Positron Anisotropies with Seven Years of Fermi Large Area Telescope Data.

The Large Area Telescope on board the Fermi Gamma-ray Space Telescope has collected the largest ever sample of high-energy cosmic-ray electron and positron events since the beginning of its operation. Potential anisotropies in the arrival directions of cosmic-ray electrons or positrons could be a signature of the presence of nearby sources. We use almost seven years of data with energies above 42 GeV processed with the Pass 8 reconstruction. The present data sample can probe dipole anisotropies down to a level of 10^{-3}. We take into account systematic effects that could mimic true anisotropies at this level. We present a detailed study of the event selection optimization of the cosmic-ray electrons and positrons to be used for anisotropy searches. Since no significant anisotropies have been detected on any angular scale, we present upper limits on the dipole anisotropy. The present constraints are among the strongest to date probing the presence of nearby young and middle-aged sources.

Helicobacter pylori and Barrett’s esophagus: a protective factor or a real cause?

Notwithstanding the definite aetiopathogenetic path of certain diseases, the relationship between Helicobacter pylori (H. pylori) and Barrett’s esophagus (BE), a condition that increases the risk for dysplasia and consequently adenocarcinoma of the distal esophagus and esophagogastric junction, remains uncertain. This paper reviews the current scientific literature with emphasis on the protective correlation between H. pylori infection and BE and demonstrates that a causal relationship has not been disproved with certainty. Furthermore, H. pylori infection could pose a risk for the onset of gastroesophageal reflux disease (GERD), which could in turn trigger BE, a precancerous lesion, and subsequently cause cancer. By analyzing the current available data, this article tries to verify that H. pylori infection is the underlying cause of esophageal cancer.

Sustainability of prevention practices at the workplace: safety, simplification, productivity and effectiveness.

Traditional full-time employment has evolved into various types of occupational situations, and, nowadays, new work organization strategies have been developed. Previously overlooked risk factors have emerged, such as traffic accidents while commuting or during work hours, poor work organization, and detrimental lifestyles (like alcohol and substance abuse, although recent statistics seem to show a declining trend for the latter). The global scenario shows greater attention to occupational risks, but also, to the reduced degree of protection. Moreover, the elevated costs, the unacceptably high fatal accident rates in some sectors, the complexity of the prevention systems, the lack of prevention training, the inadequate controls (despite the numerous independent supervisory bodies) and the obsolescence of certain precepts, call for a prompt review of the regulatory system. This is especially needed for general simplification, streamlining certification bodies and minimizing references to other provisions in the legislation that make it difficult for Italian and foreign workers to read and understand the rules "without legal interpreters". "New" occupational diseases and occupational risk factors have also been reported in addition to pollution. There are concerns for continued economic and social destabilization, unemployment, commuting, temporary and precarious contracts. All of these contribute to the lack of wellbeing in the working population. Thus, the timing, duration, and types of prevention training should be carefully assessed, making prevention more appealing by evaluating costs and benefits with a widespread use of indicators that make appropriate actions for health promotion "visible", thus encouraging awareness. Although reducing prevention is never justified, it should still be "sustainable" economically in order to avoid waste of resources. It is also essential to have laws which are easily and consistently interpreted and to work on the ethics of employers and employees to ensure that they conform to the standards of other European countries that currently operate with greater effectiveness and lower costs.

Are the school prevention programmes - aimed at de-normalizing smoking among youths - beneficial in the long term? An example from the Smoke Free Class Competition in Italy.

Tobacco smoking by young people is of great concern because it usually leads to regular smoking, nicotine addiction and quitting difficulties. Young people "hooked" by tobacco maintain the profits of the tobacco industry by replacing smokers who quit or die. If new generations could be tobacco-free, as supported by tobacco endgame strategies, the tobacco epidemic could end within decades. Smoking prevention programmes for teens are offered by schools with the aim to prevent or delay smoking onset. Among these, the Smoke Free Class Competition (SFC) was widely implemented in Europe. Its effectiveness yielded conflicting results, but it was only evaluated at short/medium term (6 - 18 months). The aim of this study is to evaluate its effectiveness after a longer follow-up (3 to 5 years) in order to allow enough time for the maturing of the students and the internalization of the experience and its contents. Fifteen classes were randomly sampled from two Italian high schools of Bologna province that regularly offered the SFC to first year students; 382 students (174 participating in the SFC and 208 controls) were retrospectively followed-up and provided their "smoking histories". At the end of their last year of school (after 5 years from the SFC), the percentage of students who stated that they were regular smokers was lower among the SFC students than in controls: 13.5% vs 32.9% (p=0.03). From the students' "smoking histories", statistically significant protective ORs were observed for SFC students at the end of 1st and 5th year: 0.42 (95% CI 0.19-0.93) and 0.32 (95% CI 0.11-0.91) respectively. Absence of smokers in the family was also a strongly statistically significant factor associated with being a non-smoker student. These results suggest that SFC may have a positive impact on lowering the prevalence of smoking in the long term (5 years).

Expression of microRNAs miR21, miR146a, and miR155 in tuberous sclerosis complex cortical tubers and their regulation in human astrocytes and SEGA-derived cell cultures.

Tuberous sclerosis complex (TSC) is a genetic disease presenting with multiple neurological symptoms including epilepsy, mental retardation, and autism. Abnormal activation of various inflammatory pathways has been observed in astrocytes in brain lesions associated with TSC. Increasing evidence supports the involvement of microRNAs in the regulation of astrocyte-mediated inflammatory response. To study the role of inflammation-related microRNAs in TSC, we employed real-time PCR and in situ hybridization to characterize the expression of miR21, miR146a, and miR155 in TSC lesions (cortical tubers and subependymal giant cell astrocytomas, SEGAs). We observed an increased expression of miR21, miR146a, and miR155 in TSC tubers compared with control and perituberal brain tissue. Expression was localized in dysmorphic neurons, giant cells, and reactive astrocytes and positively correlated with IL-1ß expression. In addition, cultured human astrocytes and SEGA-derived cell cultures were used to study the regulation of the expression of these miRNAs in response to the proinflammatory cytokine IL-1ß and to evaluate the effects of overexpression or knockdown of miR21, miR146a, and miR155 on inflammatory signaling. IL-1ß stimulation of cultured glial cells strongly induced intracellular miR21, miR146a, and miR155 expression, as well as miR146a extracellular release. IL-1ß signaling was differentially modulated by overexpression of miR155 or miR146a, which resulted in pro- or anti-inflammatory effects, respectively. This study provides supportive evidence that inflammation-related microRNAs play a role in TSC. In particular, miR146a and miR155 appear to be key players in the regulation of astrocyte-mediated inflammatory response, with miR146a as most interesting anti-inflammatory therapeutic candidate.

Erratum to: Estrogen receptor beta binds Sp1 and recruits a corepressor complex to the estrogen receptor alpha gene promoter.

Erratum to: Breast Cancer Res Treat (2012), 134:569­581, DOI 10.1007/s10549-012-2090-9. Uunfortunately, authors could not find the original film from which the figure was drawn. Therefore, as suggested by the Editor, they have repeated the relative experiment, and ask to publish this new figure as a correction. The authors apologize for any inconvenience that it may cause.

Adaptive fractionated stereotactic Gamma Knife radiotherapy of meningioma using integrated stereotactic cone-beam-CT and adaptive re-planning (a-gkFSRT).

OBJECTIVE: The Gamma Knife Icon (Elekta AB, Stockholm, Sweden) allows frameless stereotactic treatment using a combination of cone beam computer tomography (CBCT), a thermoplastic mask system, and an infrared-based high-definition motion management (HDMM) camera system for patient tracking during treatment. We report on the first patient with meningioma at the left petrous bone treated with adaptive fractionated stereotactic radiotherapy (a-gkFSRT). METHODS: The first patient treated with Gamma Knife Icon at our institute received MR imaging for preplanning before treatment. For each treatment fraction, a daily CBCT was performed to verify the actual scull/tumor position. The system automatically adapted the planned shot positions to the daily position and recalculated the dose distribution (online adaptive planning). During treatment, the HDMM system recorded the intrafractional patient motion. Furthermore, the required times were recorded to define a clinical treatment slot. RESULTS: Total treatment time was around 20 min. Patient positioning needed 0.8 min, CBCT positioning plus acquisition 1.65 min, CT data processing and adaptive planning 2.66 min, and treatment 15.6 min. The differences for the five daily CBCTs compared to the reference are for rotation: -0.59 ± 0.49°/0.18 ± 0.20°/0.05 ± 0.36° and for translation: 0.94 ± 0.52 mm/-0.08 ± 0.08 mm/-1.13 ± 0.89 mm. Over all fractions, an intrafractional movement of 0.13 ± 0.04 mm was observed. CONCLUSION: The Gamma Knife Icon allows combining the accuracy of the stereotactic Gamma Knife system with the flexibility of fractionated treatment with the mask system and CBCT. Furthermore, the Icon system introduces a new online patient tracking system to the clinical routine. The interfractional accuracy of patient positioning was controlled with a thermoplastic mask and CBCT.

In Vitro Demonstration of Dual Light-Driven Na⁺/H⁺ Pumping by a Microbial Rhodopsin.

A subfamily of rhodopsin pigments was recently discovered in bacteria and proposed to function as dual-function light-driven H(+)/Na(+) pumps, ejecting sodium ions from cells in the presence of sodium and protons in its absence. This proposal was based primarily on light-induced proton flux measurements in suspensions of Escherichia coli cells expressing the pigments. However, because E. coli cells contain numerous proteins that mediate proton fluxes, indirect effects on proton movements involving endogenous bioenergetics components could not be excluded. Therefore, an in vitro system consisting of the purified pigment in the absence of other proteins was needed to assign the putative Na(+) and H(+) transport definitively. We expressed IAR, an uncharacterized member from Indibacter alkaliphilus in E. coli cell suspensions, and observed similar ion fluxes as reported for KR2 from Dokdonia eikasta. We purified and reconstituted IAR into large unilamellar vesicles (LUVs), and demonstrated the proton flux criteria of light-dependent electrogenic Na(+) pumping activity in vitro, namely, light-induced passive proton flux enhanced by protonophore. The proton flux was out of the LUV lumen, increasing lumenal pH. In contrast, illumination of the LUVs in a Na(+)-free suspension medium caused a decrease of lumenal pH, eliminated by protonophore. These results meet the criteria for electrogenic Na(+) transport and electrogenic H(+) transport, respectively, in the presence and absence of Na(+). The direction of proton fluxes indicated that IAR was inserted inside-out into our sealed LUV system, which we confirmed by site-directed spin-label electron paramagnetic resonance spectroscopy. We further demonstrate that Na(+) transport by IAR requires Na(+) only on the cytoplasmic side of the protein. The in vitro LUV system proves that the dual light-driven H(+)/Na(+) pumping function of IAR is intrinsic to the single rhodopsin protein and enables study of the transport activities without perturbation by bioenergetics ion fluxes encountered in vivo.

Cation-Specific Conformations in a Dual-Function Ion-Pumping Microbial Rhodopsin.

A recently discovered rhodopsin ion pump (DeNaR, also known as KR2) in the marine bacterium Dokdonia eikasta uses light to pump protons or sodium ions from the cell depending on the ionic composition of the medium. In cells suspended in a KCl solution, DeNaR functions as a light-driven proton pump, whereas in a NaCl solution, DeNaR conducts light-driven sodium ion pumping, a novel activity within the rhodopsin family. These two distinct functions raise the questions of whether the conformations of the protein differ in the presence of K(+) or Na(+) and whether the helical movements that result in the canonical E → C conformational change in other microbial rhodopsins are conserved in DeNaR. Visible absorption maxima of DeNaR in its unphotolyzed (dark) state show an 8 nm difference between Na(+) and K(+) in decyl maltopyranoside micelles, indicating an influence of the cations on the retinylidene photoactive site. In addition, electronic paramagnetic resonance (EPR) spectra of the dark states reveal repositioning of helices F and G when K(+) is replaced with Na(+). Furthermore, the conformational changes assessed by EPR spin-spin dipolar coupling show that the light-induced transmembrane helix movements are very similar to those found in bacteriorhodopsin but are altered by the presence of Na(+), resulting in a new feature, the clockwise rotation of helix F. The results establish the first observation of a cation switch controlling the conformations of a microbial rhodopsin and indicate specific interactions of Na(+) with the half-channels of DeNaR to open an appropriate path for ion translocation.