Neurosurgical treatment of pediatric brain tumors - results from a single center multidisciplinary setup.

OBJECTIVE: The challenge of pediatric brain tumor surgery is given due to a relative low prevalence but high heterogeneity in age, localization, and pathology. Improvements of long-term overall survival rates were achieved during the past decades stressing the importance of a multidisciplinary decision process guided by a national treatment protocol. We reviewed the entire spectrum of pediatric brain tumor surgeries from the perspective of an interdisciplinary pediatric neuro-oncology center in Germany. METHODS: Every patient who underwent brain tumor surgery from January 2010 to June 2017 in our Pediatric Neurosurgery department was retrospectively included and evaluated regarding the course of treatment. Perioperative data such as tumor localization, timing of surgery, extent of resection, neuropathological diagnosis, transfusion rates, oncologic and radiation therapy, and neurological follow-up including morbidity and mortality were evaluated. RESULTS: Two hundred ninety-three pediatric brain tumor patients were applicable (age: 8.28 ± 5.62 years, 1.22:1.0 m:f). A total of 531 tumor surgical interventions was performed within these patients (457 tumor resections, 74 tumor biopsies; mean interventions per patient 1.8 ± 1.2). Due to a critical neurologic status, 32 operations (6%) were performed on the day of admission. In 65.2% of all cases, tumor were approached supratentorially. Most frequent diagnoses of the cases were glial tumors (47.8%) and embryonal tumors (17.6%). Preoperative planned extent of resection was achieved in 92.7%. Pre- and postoperative neurologic deficits resolved completely in 30.7%, whereas symptom regressed in 28.6% of surgical interventions. New postoperative neurologic deficit was observed in 10.7%, which resolved or improved in 80% of these cases during 30 days. The mortality rate was 1%. CONCLUSION: We outlined the center perspective of a specialized pediatric neuro-oncological center describing the heterogeneous distribution of cases regarding age-related prevalence, tumor localization, and biology, which requires a high multidisciplinary expertise. The study contributes to define challenges in treating pediatric brain tumors and to develop quality indicators for pediatric neuro-oncological surgery. We assume that an adequate volume load of patients within a interdisciplinary infrastructure is warranted to aim for effective treatment and decent quality of life for the majority of long-term surviving pediatric tumor patients.

Robotic stereotactic ablative radiotherapy for renal cell carcinoma in patients with impaired renal function.

BACKGROUND: Robotic stereotactic ablative radiotherapy (SABR) is currently under investigation as a noninvasive treatment option for patients with renal cell carcinoma (RCC). For radiation therapy of RCC, tumor motion and the need for high ablative doses while preserving the remaining renal parenchyma is a challenge. We aimed to analyze the safety and efficacy of robotic radiosurgery in RCC in a specific difficult subgroup of patients with impaired renal function. METHODS: We retrospectively identified all patients with RCC, treated with robotic SABR and motion compensation in our institution between 2012 and 2017. Either single fraction SABR of 24 or 25 Gy or 3 fractions of 12 Gy prescribed to the 70% isodose line was applied. Local control, overall survival, radiation side effects were evaluated together with renal function and tumor motion. RESULTS: We analyzed data of 13 lesions treated in 10 patients with clear cell RCC and a mean age of 70.5 ± 13.6 years (range: 48-87). Prior to SABR, 8 patients underwent previous complete and/or partial nephrectomy, 7 patients presented with chronic kidney disease ≥ stage 3. The median of minimum, mean and maximum planning target volume doses were 23.2, 29.5 and 35.0 Gy for single fraction and 24.4, 42.5 and 51.4 Gy for the three fractions regime. Persistent local control by robotic SABR was achieved in 9 out of 10 patients (92.3% of all lesions) within a median follow-up period of 27 month (range: 15-54). One patient underwent nephrectomy due to progressive disease and sufficient renal function of the contralateral kidney. Renal function remained stable with a mean estimated glomerular filtration rate (eGFR) of 51.3 ± 19.7 ml/min at baseline and 51.6 ± 25.8 ml/min at follow-up. The largest respiratory-induced tumor motion was seen in superior-inferior direction, compensated by the CyberKnife with mean targeting errors of maximal 2.2 mm. CONCLUSIONS: Robotic SABR is technically feasible for the treatment of RCC in preexisting kidney disease with good local tumor control at about 2 years follow-up. Robotic SABR with motion tracking offers a valid treatment option for patients, who are at increased risk for progression to end-stage renal disease due to partial nephrectomy or ablative techniques.

Effects of polystyrene nanoparticles on the microbiota and functional diversity of enzymes in soil.

BACKGROUND: The increasing production of nanoplastics and the fragmentation of microplastics into smaller particles suggest a plausible yet unclear hazard in the natural environment, such as soil. We investigated the short-term effects (28 days) of polystyrene nanoparticles (PS-NPs) on the activity and biomass of soil microbiota, and the functional diversity of soil enzymes at environmental relevant low levels in an incubation experiment. RESULTS: Our results showed a significant decrease in microbial biomass in treatments of 100 and 1000 ng PS-NP g-1 DM throughout the incubation period. Dehydrogenase activity and activities of enzymes involved in N-(leucine-aminopeptidase), P-(alkaline-phosphatase), and C-(ß-glucosidase and cellobiohydrolase) cycles in the soil were significantly reduced at day 28 suggesting a broad and detrimental impact of PS-NPs on soil microbiota and enzymes. Leucine-aminopeptidase and alkaline-phosphatase activities tended to decrease consistently, while ß-glucosidase and cellobiohydrolase activities increased at high concentrations (e.g., PS-NP-1000) in the beginning of the incubation period, e.g., at day 1. On the other hand, basal respiration and metabolic quotient increased with increasing PS-NP application rate throughout the incubation period possibly due to increased cell death that caused substrate-induced respiration (cryptic growth). CONCLUSIONS: We herewith demonstrated for the first time the potential antimicrobial activity of PS-NPs in soil, and this may serve as an important resource in environmental risk assessment of PS-NPs in the soil environment.

Identification and expression profiling of Pht1 phosphate transporters in wheat in controlled environments and in the field.

Phosphorus (P) is an important macronutrient with critical functions in plants. Phosphate (Pi) transporters, which mediate Pi acquisition and Pi translocation within the plant, are key factors in Pi deficiency responses. However, their relevance for adaptation to long-term Pi limitation under agronomic conditions, particularly in wheat, remains unknown. Here, we describe the identification of the complete Pi transporter gene family (Pht1) in wheat (Triticum aestivum). Gene expression profiles were compared for hydroponic and field-grown plant tissues of wheat at multiple development stages. Cis-element analysis of selected Pht1 promoter regions was performed. A broad range of expression patterns of individual TaPht1 genes was observed in relation to tissue specificity and the nutrient supply in the soil or in liquid culture, as well as an influence of the experimental system. The expression patterns indicate the involvement of specific transporters in Pi uptake, and in Pi transport and remobilisation within the plant, at different growth developmental stages. Specifically, the influence of Pi nutrition indicates a complex regulatory pattern of TaPht1 gene transcript abundances as a response to low Pi availability in different culture systems, correlating with the existence of different cis-acting promoter elements.

Three-wave mixing mediated femtosecond pulse compression in ß-barium borate.

Nonlinear pulse compression mediated by three-wave mixing is demonstrated for ultrashort Ti:sapphire pulses in a type II phase-matched ß-barium borate (BBO) crystal using noncollinear geometry. 170 µJ pulses at 800 nm with a pulse duration of 74 fs are compressed at their sum frequency to 32 fs with 55 µJ of pulse energy. Experiments and computer simulations demonstrate the potential of sum-frequency pulse compression to match the group velocities of the interacting waves to crystals that were initially not considered in the context of nonlinear pulse compression.

In-depth exploration of the photophysics of a trinuclear palladium complex.

A detailed theoretical and spectroscopic study on the electronically excited states of a trinuclear palladium complex is presented both in the gas phase and solution. The application of DFT and TDDFT methods as well as a variety of spectroscopic methods to the chosen complex [Pd3{Si(mt(Me))3}2] (1, mt(Me) = methimazole) leads to the first detailed analysis of the photophysics of a symmetric trinuclear complex. In combination with the calculations, energies, structures and lifetimes of the excited electronic states (with an (3)A1 state as the lowest one) are characterized by applying the resonant-2-photon-ionization method in a molecular beam experiment as well as luminescence, time-correlated single photon counting and excited state femtosecond absorption spectroscopy in solution. These investigations are of fundamental interest to analyze photophysical properties of metal containing complexes on a molecular level.

Oligometastases: the new paradigm and options for radiotherapy. A critical review.

Traditional oncology distinguishes between two separate and incommensurable states in the evolution of solid malignancies: the localized disease, which is curable; and the disseminated status, which is per se palliative. Recently, a huge body of evidence suggests a fundamental change in the understanding of cancer, indicating an intermediate state in the trajectory of solid malignancies: the oligometastatic state. The following review will critically analyse existing hypotheses and facts from the basic sciences and try to contextualize it in regard to the clinical evidence available to date. Consecutively, it will try to draw possible clinical consequences for application of radiotherapy in this specific clinical scenario.

N-heterocyclic dronic acids: applications and synthesis.

Substituted hydroxymethylenebisphosphonic acid derivatives--either as dronic acids or their dronate sodium salts, are important pharmaceuticals in the treatment of diseases arising from excessive bone-resorption. Potential has also been identified in areas ranging from parasite-growth inhibition to immunological and cancer therapeutics. Representative clinically relevant N-heterocyclic derivatives include zoledronic and risedronic acids. The biochemical background and mechanism of action of these drugs are discussed, along with trends in structural development and future prospects. Synthetic routes to dronates are then summarized. The most popular route to valuable dronic acids involves the 3- component condensation of a substituted acetic acid, phosphorous acid, and phosphorus trichloride. However, the protocols recorded in the literature are very diverse. This review gives a critical account of reported methods, explores the contradictions and suggests a practical synthetic procedure after clarifying the inconsistencies described. Possible mechanisms of the reaction are also discussed.

Wavelength dependence of the suppressed ionization of molecules in strong laser fields.

We study ionization of molecules by an intense laser field over a broad wavelength regime, ranging from 0.8 to 1.5 µm experimentally and from 0.6 to 10 µm theoretically. A reaction microscope is combined with an optical parametric amplifier to achieve ionization yields in the near-infrared wavelength regime. Calculations are done using the strong-field S-matrix theory and agreement is found between experiment and theory, showing that ionization of many molecules is suppressed compared to the ionization of atoms with identical ionization potentials at near-infrared wavelengths at around 0.8 µm, but not at longest wavelengths (10 µm). This is due to interference effects in the electron emission that are effective at low photoelectron energies but tend to average out at higher energies. We observe the transition between suppression and nonsuppression of molecular ionization in the near-infrared wavelength regime (1-5 µm).

Few-cycle pulse characterization with an acousto-optic pulse shaper.

An acousto-optic pulse shaper has been used to characterize few-cycle pulses generated in a hollow-core fiber. A grism pair precompensates for the dispersion of the acousto-optic crystal, allowing the full pulse-shaping window to be used for replica generation rather than self-compensation. A 9.4 fs pulse was measured, the shortest ever measured with an acousto-optic pulse shaper, to our knowledge.

The era of centers: the influence of establishing specialized centers on patients' choice of hospital.

PURPOSE: It is considered that establishing accredited specialized centers can serve as a marketing tool. This study investigated whether accredited specialized centers influence patients' choice of hospital. METHODS: A total of 2,389 patients was included in a questionnaire survey: 468 at the Department of Gynecology, 745 at the certified University Breast Center of Franconia, 1,000 at the University Perinatal Center of Franconia and 176 for whom classification details were lacking. RESULTS: Among the oncological patients, physicians in private practice played an important role in the choice of hospital (58.4 vs. 25.7%; P < 0.001; OR 4.058). Among obstetric patients, the primary factors were recommendations from family [odds ratio (OR) 0.495], friends (OR 0.218), and previous personal experience of the hospital (OR 0.695). For oncological patients, treatment quality (OR 2.693), availability of a center (OR 1.785), and certification (OR 3.939) were comparatively more important. For obstetric patients, friendliness (OR 0.409) and attractive accommodation (OR 0.153) were more important. CONCLUSIONS: Physicians are the most important source of recommendations for oncological patients. From the marketing point of view, intensive involvement of local private-practice physicians is necessary. The availability of certified perinatal centers does not currently play any part in patients' choice of hospital.

[Surgical therapy of basalioma of the facial skin]. / Die chirurgische Therapie des Gesichtshautbasalioms.

The present investigation reviews the history of 673 patients having undergone surgical treatment for 1301 BCC of the face between 1977 and 1992 at our department. Based on this series the features with bearing on the surgical strategy, such as type, size and location of the lesions, will be outlined. Emphasis is put on the variants of local flap reconstruction and skin grafting techniques, particularly in the problem zones of the nose and eyelids, where no excess skin for closure of the defect is available. Throughout the whole series histologic control of the adequacy of marginal and deep tumor resection was performed. It became obvious that the required ranges for clearance to tumor edges and removal in depth cannot be predefined arbitrarily or on pure clinical judgement. Frequently a two-stage procedure of resection and repair will be necessitated. Recurrences during the mandatory follow-up were thoroughly reassessed to identify the reason for failure (e.g. accuracy of histologic category, multifocal growth, predisposition) and related to the time span from primary excision. Our series confirms that morphologically controlled surgical excision of the BCC of the face and subsequent application of reconstructive techniques produces both safe oncologic and esthetic results.

[A case of painful bilateral ophthalmoplegia]. / A propos d'un cas d'ophtalmoplégie bilatérale douloureuse.

The authors present a case of Tolosa-Hunt syndrome with the particularity of a simultaneous palsy of both oculomotor nerves. The evolution is followed during 16 years. The clinical description, the criteria of the syndrome and the differential diagnosis are discussed. The diagnosis is based on the clinical evolution, the transitory palsy of the oculomotor nerves and the involvement of the optic nerve. The response on steroid treatment was spectacular. Bilateral and fluctuant oculomotor palsy is possible in the TolosaHunt syndrome. General investigations are mandatory to exclude other pathologies.

Chromogenic calix[4]arene as ionophore for potentiometric and optical sensors.

Chromogenic calix[4]arene derivative was synthesized and tested as an ionophore for potentiometric and optical sensors. Distinct sodium selectivity was observed with this ionophore based, plasticized PVC membranes in potentiometric measurements suggesting their utility for biological applications. Optode membranes exhibited sodium sensitivity in the 5 x 10(-2) -10(-4)M concentration range. The optical sensitivity was improved by the use of an internal, lipophilic base (TDDA). The operation of the optical sensor is in accordance with the ion-exchange theory.