Characterization of Commercially Available Human Primary Alveolar Epithelial Cells

In vitro lung research requires appropriate cell culture models that adequately mimic in vivo structure and function. Previously, researchers extensively used commercially available and easily expandable A549 and NCI-H441 cells, which replicate some but not all features of alveolar epithelial cells. Specifically, these cells are often restricted by terminally altered expression while lacking important alveolar epithelial characteristics. Of late, human primary alveolar epithelial cells (hPAEpCs) have become commercially available but are so far poorly specified. Here, we applied a comprehensive set of technologies to characterize their morphology, surface marker expression, transcriptomic profile, and functional properties. At optimized seeding numbers of 7,500 cells per square centimeter and growth at a gas-liquid interface, hPAEpCs formed regular monolayers with tight junctions and amiloride-sensitive transepithelial ion transport. Electron microscopy revealed lamellar body and microvilli formation characteristic for alveolar type II cells. Protein and single-cell transcriptomic analyses revealed expression of alveolar type I and type II cell markers; yet, transcriptomic data failed to detect NKX2-1, an important transcriptional regulator of alveolar cell differentiation. With increasing passage number, hPAEpCs transdifferentiated toward alveolar-basal intermediates characterized as SFTPC-, KRT8high, and KRT5- cells. In spite of marked changes in the transcriptome as a function of passaging, Uniform Manifold Approximation and Projection plots did not reveal major shifts in cell clusters, and epithelial permeability was unaffected. The present work delineates optimized culture conditions, cellular characteristics, and functional properties of commercially available hPAEpCs. hPAEpCs may provide a useful model system for studies on drug delivery, barrier function, and transepithelial ion transport in vitro.

Expert proposal to analyze the combination of aortic and mitral regurgitation in multiple valvular heart disease by comprehensive echocardiography

The assessment of valvular pathologies in multiple valvular heart disease by echocardiography remains challenging. Data on echocardiographic assessment-especially in patients with combined aortic and mitral regurgitation-are rare in the literature. The proposed integrative approach using semi-quantitative parameters to grade the severity of regurgitation often yields inconsistent findings and results in misinterpretation. Therefore, this proposal aims to focus on a practical systematic echocardiographic analysis to understand the pathophysiology and hemodynamics in patients with combined aortic and mitral regurgitation. The quantitative approach of grading the regurgitant severity of each compound might be helpful in elucidating the scenario in combined aortic and mitral regurgitation. To this end, both the individual regurgitant fraction of each valve and the total regurgitant fraction of both valves must be determined. This work also outlines the methodological issues and limitations of the quantitative approach by echocardiography. Finally, we present a proposal that enables verifiable assessment of regurgitant fractions. The overall interpretation of echocardiographic results includes the symptomatology of patients with combined aortic and mitral regurgitation and the individual treatment options with respect to their individual risk. In summary, a reproducible, verifiable, and transparent in-depth echocardiographic investigation might ensure consistent hemodynamic plausibility of the quantitative results in patients with combined aortic and mitral regurgitation.

Biocellulose patch technique for fetoscopic repair of open spina bifida in twin pregnancy

OBJECTIVES

Twin pregnancy is currently an exclusion criterion for prenatal repair of open spina bifida (OSB). The main objective of this study was to report on our experience of treating twin pregnancies with OSB using the skin-over-biocellulose for antenatal fetoscopic repair (SAFER) technique. We also discuss reconsideration of the current exclusion criteria for fetal OSB repair.

METHODS

Eight fetuses with OSB from seven twin pregnancies underwent successful prenatal repair. Six pregnancies were dichorionic diamniotic with only one twin affected, and one was monochorionic diamniotic with both twins affected. Percutaneous fetoscopy was performed under CO2 insufflation of the sac of the affected twin. Neurosurgical repair was performed using a biocellulose patch to protect the placode, with the skin sutured to hold the patch in place, with or without a myofascial flap. Neurodevelopment was assessed using the pediatric evaluation of disability inventory scale in babies older than 6 months of adjusted age, whereas the Alberta scale was used for babies younger than 6 months of adjusted age.

RESULTS

All 14 fetuses were liveborn and none required additional repair. Gestational age at surgery ranged from 27.3 to 31.1 weeks, and gestational age at birth ranged from 31.6 to 36.0 weeks. Four out of eight affected twins developed sepsis, but had a good recovery. No sequela of prematurity was found in any of the unaffected twins. Short-term neurodevelopment was normal in all evaluated unaffected twins (5/5) and in all but one affected twins (7/8). In the affected group, only one baby required ventriculoperitoneal shunt placement.

CONCLUSIONS

Prematurity is frequent after fetal surgery, and the risk is increased in twin pregnancy. Nevertheless, prenatal surgery using the SAFER technique is feasible, with low risk to both twins and their mother when performed by a highly experienced team. Long-term cognitive assessment of the unaffected twin is needed. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Expert proposal to characterize cardiac diseases with normal or preserved left ventricular ejection fraction and symptoms of heart failure by comprehensive echocardiography

Currently, the term "heart failure with preserved left ventricular ejection fraction (HFpEF)" is based on echocardiographic parameters and clinical symptoms combined with elevated or normal levels of natriuretic peptides. Thus, "HFpEF" as a diagnosis subsumes multiple pathophysiological entities making a uniform management plan for "HFpEF" impossible. Therefore, a more specific characterization of the underlying cardiac pathologies in patients with preserved ejection fraction and symptoms of heart failure is mandatory. The present proposal seeks to offer practical support by a standardized echocardiographic workflow to characterize specific diagnostic entities associated with "HFpEF". It focuses on morphological and functional cardiac phenotypes characterized by echocardiography in patients with normal or preserved left ventricular ejection fraction (LVEF). The proposal discusses methodological issues to clarify why and when echocardiography is helpful to improve the diagnosis. Thus, the proposal addresses a systematic echocardiographic approach using a feasible algorithm with weighting criteria for interpretation of echocardiographic parameters related to patients with preserved ejection fraction and symptoms of heart failure. The authors consciously do not use the diagnosis "HFpEF" to avoid misunderstandings. Central illustration: Scheme illustrating the characteristic echocardiographic phenotypes and their combinations in patients with "HFpEF" symptoms with respect to the respective cardiac pathology and pathophysiology as well as the underlying typical disease.

P08.12.B Conceptual development of an intensive supervised exercise program for brain tumor patients: summary of clinical experience

Background

Several studies have identified beneficial effects of physical activity on reducing cancer-related symptoms. However, the number of such studies in neuro-oncology is limited, and even today, brain tumor patients are often advised against physically strenuous exercise. Here we summarize our experience with an individualized training program in brain tumor patients over a period of more than 8 years.

Material and Methods

Patients with primary brain tumors were invited to participate in the individual training program as part of the psycho-oncological consultation. If interested and free of major comorbidity, a professional sport scientist/diploma coach individualized two 60-minute sessions/week adapted to the patients’ respective symptoms and trained them on a 1:1-basis. One session consisted of bicycle ergometry at an average workload of 75% of the max. age-adjusted heart rate (up to 95% at peak; continuous monitoring throughout entire session), the other session was progressive whole-body resistance training based on 10 separate, but standardized exercise tasks using the university’s training facilities. Both training sessions were complimented by challenging elements to improve coordination. Exercise tasks were adapted as needed, and exercise levels were enhanced over time, if possible.

Results

From 2011 to 2019, 45 patients (19 women, 26 men) aged 20-76 years (mean 49) with different tumor types (65% high-grade gliomas, 22% low-grade gliomas, 13% other) participated in the program. The majority of patients started the program following concurrent radio-chemotherapy and in parallel with adjuvant systemic therapy. On average, 41 training sessions were performed. No training-related adverse events (e.g., falls, head pain, etc.) occurred during the entire period. In a total of 1828 training sessions, two minor epileptic seizures occurred (1 speech arrest; 1 simple focal seizure, left hand affected). Both patients were familiar with the respective type of seizure before entering the program and training could be continued immediately, with reduced intensity. Seizures did not reoccur during subsequent training sessions.

Conclusion

This supervised intensive physical training program with submaximal exertion zones was feasible, safe, and highly rated by all participants. Based on these experiences and the reported well-being of the patients, we launched a prospective oligocentric study to objectify the improvements in physical performance and quality of life in patients with glioblastoma (ClinicalTrials.gov Identifier: NCT05015543).

Monte Carlo analysis of accelerator-driven systems: Studies on spallation neutron yield and energy gain

The neutron yield in the interaction of protons with lead and uranium targets has been studied using the LAHET code system. The dependence of the neutron multiplicity on target dimensions and proton energy has been calculated and the dependence of the energy amplification on the proton energy has been investigated in an accelerator-driven system of a given effective multiplication coefficient. Some of the results are compared with experimental findings and with similar calculations by the DCM/CEM code of Dubna and the FLUKA code system used in CERN.

Subcritical nuclear systems and their stability against changes in the geometrical set-up

A specific subcritical reactor system has been suggested and the stability of its parameters against small changes in the geometrical set-up has been estimated using the model calculation code DCM/CEM from Dubna. The dimensions of the system are 200 cm in diameter and 170 cm in length and it supplies a thermal power of 900 MW with keff =0.943, using a 20 mA proton beam of an energy of 1 GeV. Considering the thermal → electricity power and electricity → beam power conversion efficiencies, the electric power amplification is about 8. Energy deposition and neutron energy distribution in the fission core are also studied. Some properties, such as the heat production per unit volume, are rather similar to modern fast breeders. The neutron multiplication factor keff is very sensitive to small changes in the geometrical set-up within the fission core.

Metabolic Glycoengineering Enables the Ultrastructural Visualization of Sialic Acids in the Glycocalyx of the Alveolar Epithelial Cell Line hAELVi

The glycocalyx—a plethora of sugars forming a dense layer that covers the cell membrane—is commonly found on the epithelial surface of lumen forming tissue. New glycocalyx specific properties have been defined for various organs in the last decade. However, in the lung alveolar epithelium, its structure and functions remain almost completely unexplored. This is partly due to the lack of physiologically relevant, cost effective in vitro models. As the glycocalyx is an essential but neglected part of the alveolar epithelial barrier, understanding its properties holds the promise to enhance the pulmonary administration of drugs and delivery of nanoparticles. Here, using air-liquid-interface (ALI) cell culture, we focus on combining metabolic glycoengineering with glycan specific electron and confocal microscopy to visualize the glycocalyx of a recently immortalized human alveolar epithelial cell line (hAELVi). For this purpose, we applied different bioorthogonal labeling approaches to visualize sialic acid—an amino sugar that provides negative charge to the lung epithelial glycocalyx—using both fluorescence and gold-nanoparticle labeling. Further, we compared mild chemical fixing/freeze substitution and standard cytochemical electron microscopy embedding protocols for their capacity of contrasting the glycocalyx. In our study, we established hAELVi cells as a convenient model for investigating human alveolar epithelial glycocalyx. Transmission electron microscopy revealed hAELVi cells to develop ultrastructural features reminiscent of alveolar epithelial type II cells (ATII). Further, we visualized extracellular uni- and multilamellar membranous structures in direct proximity to the glycocalyx at ultrastructural level, indicating putative interactions. The lamellar membranes were able to form structures of higher organization, and we report sialic acid to be present within those. In conclusion, combining metabolite specific glycoengineering with ultrastructural localization presents an innovative method with high potential to depict the molecular distribution of individual components of the alveolar epithelial glycocalyx and its interaction partners.

Plasma Membrane Fusion Is Specifically Impacted by the Molecular Structure of Membrane Sterols During Vegetative Development of Neurospora crassa

Cell-to-cell fusion is crucial for the development and propagation of most eukaryotic organisms. Despite this importance, the molecular mechanisms mediating this process are only poorly understood in biological systems. In particular, the step of plasma membrane merger and the contributing proteins and physicochemical factors remain mostly unknown. Earlier studies provided the first evidence of a role of membrane sterols in cell-to-cell fusion. By characterizing different ergosterol biosynthesis mutants of the fungus Neurospora crassa, which accumulate different ergosterol precursors, we show that the structure of the sterol ring system specifically affects plasma membrane merger during the fusion of vegetative spore germlings. Genetic analyses pinpoint this defect to an event prior to engagement of the fusion machinery. Strikingly, this effect is not observed during sexual fusion, suggesting that the specific sterol precursors do not generally block membrane merger, but rather impair subcellular processes exclusively mediating fusion of vegetative cells. At a colony-wide level, the altered structure of the sterol ring system affects a subset of differentiation processes, including vegetative sporulation and steps before and after fertilization during sexual propagation. Together, these observations corroborate the notion that the accumulation of particular sterol precursors has very specific effects on defined cellular processes rather than nonspecifically disturbing membrane functioning. Given the phenotypic similarities of the ergosterol biosynthesis mutants of N. crassa during vegetative fusion and of Saccharomyces cerevisiae cells undergoing mating, our data support the idea that yeast mating is evolutionarily and mechanistically more closely related to vegetative than sexual fusion of filamentous fungi.

Evolution of morphology and locomotor performance in anurans: relationships with microhabitat diversification

The relationships between morphology, performance, behavior and ecology provide evidence for multiple and complex phenotypic adaptations. The anuran body plan, for example, is evolutionarily conserved and shows clear specializations to jumping performance back at least to the early Jurassic. However, there are instances of more recent adaptation to habit diversity in the post-cranial skeleton, including relative limb length. The present study tested adaptive models of morphological evolution in anurans associated with the diversity of microhabitat use (semi-aquatic arboreal, fossorial, torrent, and terrestrial) in species of anuran amphibians from Brazil and Australia. We use phylogenetic comparative methods to determine which evolutionary models, including Brownian motion (BM) and Ornstein-Uhlenbeck (OU) are consistent with morphological variation observed across anuran species. Furthermore, this study investigated the relationship of maximum distance jumped as a function of components of morphological variables and microhabitat use. We found there are multiple optima of limb lengths associated to different microhabitats with a trend of increasing hindlimbs in torrent, arboreal, semi-aquatic whereas fossorial and terrestrial species evolve toward optima with shorter hindlimbs. Moreover, arboreal, semi-aquatic and torrent anurans have higher jumping performance and longer hindlimbs, when compared to terrestrial and fossorial species. We corroborate the hypothesis that evolutionary modifications of overall limb morphology have been important in the diversification of locomotor performance along the anuran phylogeny. Such evolutionary changes converged in different phylogenetic groups adapted to similar microhabitat use in two different zoogeographical regions.

Application of alpha/theta neurofeedback and heart rate variability training to young contemporary dancers: state anxiety and creativity

As one in a series on the impact of EEG-neurofeedback in the performing arts, we set out to replicate a previous dance study in which alpha/theta (A/T) neurofeedback and heart rate variability (HRV) biofeedback enhanced performance in competitive ballroom dancers compared with controls. First year contemporary dance conservatoire students were randomised to the same two psychophysiological interventions or a choreology instruction comparison group or a no-training control group. While there was demonstrable neurofeedback learning, there was no impact of the three interventions on dance performance as assessed by four experts. However, HRV training reduced anxiety and the reduction correlated with improved technique and artistry in performance; the anxiety scale items focussed on autonomic functions, especially cardiovascular activity. In line with the putative impact of hypnogogic training on creativity A/T training increased cognitive creativity with the test of unusual uses, but not insight problems. Methodological and theoretical implications are considered.

The chemical separation of Eka-Hg from CERN W targets in view of recent relativistic calculations

In 1971 evidence for the production of element 112 via secondary reactions in CERN W targets was obtained. The evidence was mainly based on the observation of fission fragments in Hg sources separated from the W targets, on the measured masses of the fissioning nuclei and on the assumption that element 112 (Eka-Hg) actually behaves like Hg in the chemical separation process. This assumption is analyzed in view of recent relativistic calculations of the electronic structure of element 112. It is shown that in the superheavy element region only the chemistry of element 112 is similar to that of Hg.

Comments on the question of the discovery of element 112 as early as 1971

There are two independent claims for the discovery of element 112: The claim by Hofmann et al. from 1996 and the older claim from 1971 by Marinov et al. This Comment will not challenge the experimental results of Hofmann et al., but it will discuss one aspect of the claimed discovery of element 112 by Marinov et al., as their experiment has never been reproduced in exactly the form in which the original experiment has been carried out. The reasons for this deficiency may not be found in the field of science, but possibly in radioprotection restrictions for researchers who want to carry out such an experiment. However, such is not a sufficient reason to exclude the original claim from all considerations of the responsible international authorities, who have to settle such priority questions. It may be in agreement with scientific traditions, that when the responsible international committees do not feel to be able to come to a positive decision on the “1971” claim, they could keep the priority problem unsettled for the time being.

Accelerator driven systems for transmutation and energy production: challenges and dangers

Accelerator Driven Systems (ADS) are an old technological idea: Relativistic proton accelerators deliver their beams onto massive heavy element targets, thus producing abundant neutron fluences. Placing this target into sub-critical nuclear fission assemblies is yielding substantial fission reactions, thus additional fission energy (Rubbia called such a system “Energy Amplifier”). This technology has recently attracted considerable attention due to advances in the construction of powerful accelerators. It allows the safe and cheap production of nuclear energy simultaneously with the destruction (Transmutation) of long lived radioactive waste, in particular plutonium and other minor actinides (neptunium and americium). The principles and the present-state-of-the-art are described, including first experiments to transmute plutonium this way. This technology needs, however, many more years of further “research and development” before large scale ADS's can be constructed. It may be even necessary to investigate the question, if all basic physics phenomena of this technology are already sufficiently well understood.

PG545, a dual heparanase and angiogenesis inhibitor, induces potent anti-tumour and anti-metastatic efficacy in preclinical models

Background:

PG545 is a heparan sulfate (HS) mimetic that inhibits tumour angiogenesis by sequestering angiogenic growth factors in the extracellular matrix (ECM), thus limiting subsequent binding to receptors. Importantly, PG545 also inhibits heparanase, the only endoglycosidase which cleaves HS chains in the ECM. The aim of the study was to assess PG545 in various solid tumour and metastasis models.

Methods:

The anti-angiogenic, anti-tumour and anti-metastatic properties of PG545 were assessed using in vivo angiogenesis, solid tumour and metastasis models. Pharmacokinetic (PK) data were also generated in tumour-bearing mice to gain an understanding of optimal dosing schedules and regimens.

Results:

PG545 was shown to inhibit angiogenesis in vivo and induce anti-tumour or anti-metastatic effects in murine models of breast, prostate, liver, lung, colon, head and neck cancers and melanoma. Enhanced anti-tumour activity was also noted when used in combination with sorafenib in a liver cancer model. PK data revealed that the half-life of PG545 was relatively long, with pharmacologically relevant concentrations of radiolabeled PG545 observed in liver tumours.

Conclusion:

PG545 is a new anti-angiogenic clinical candidate for cancer therapy. The anti-metastatic property of PG545, likely due to the inhibition of heparanase, may prove to be a critical attribute as the compound enters phase I clinical trials.

Changes in microtubule turnover accompany synaptic plasticity and memory formation in response to contextual fear conditioning in mice

Synaptic plasticity plays a crucial role in learning, memory, and cognitive disorders. Cytoskeletal reorganization underlies neuronal synaptic plasticity, but little is known about the regulation of cytoskeletal dynamics in living animals. We used stable isotope labeling to measure the turnover of tubulin in defined microtubule (MT) populations in murine brain. Neuronal MTs generally exhibited low turnover rates in vivo. Basal turnover was highest in tau-associated MTs, intermediate in microtubule-associated protein 2 (MAP2)-associated MTs, and lowest in cold-stable MTs. Labeling of MTs in mature neurons in cell culture yielded similar turnover results. Intracerebroventricular glutamate injection stimulated, via N-methyl-D-aspartic acid receptors, label incorporation (turnover) in cold-stable, tau-associated, and MAP2-associated MTs, the last of which was shown to be dependent on cyclic adenosine-3', 5'-monophosphorothioate-protein kinase A. Contextual fear conditioning, a hippocampus-mediated form of memory formation, was accompanied by increased turnover of hippocampal MAP2-associated and cold-stable MTs. Treatment with the MT-depolymerizing drug nocodazole reversed the conditioning-induced increase in label incorporation in MAP2-associated MTs, reduced dendritic spine density, and impaired memory formation. The effects of nocodazole on MT turnover were prevented by the MT-stabilizing agent Taxol (Sigma-Aldrich, St. Louis, MO, USA) and by brain-derived nerve growth factor, both of which also restored dendritic spine density and memory formation in this model. In conclusion, these results suggest that changes in hippocampal MT turnover are required for, and are a biomarker of, the synaptic plasticity that is involved in memory formation.

Socioeconomic Factors Influencing BRCA 1/2 Mutation Carriers To Choose Risk Reduction Surgery in Community Cancer Genetics Program

Background: Mutations in the BRCA 1/2 genes predispose women to increased risk of breast and ovarian cancer. Prophylactic mastectomy (PM) reduces the risk of breast cancer by approximately 90% while prophylactic salpingo-oophorectomy (PSO) reduces the risk of both breast and ovarian cancer. Yet, there is a paucity of data to determine if mutation carriers avail themselves of these risk reducing surgeries in the community setting.Purpose: This study evaluates if particular socioeconomic factors influence BRCA 1/2 mutation carriers to elect risk reduction surgery (RRS), either PM or PSO or both.Method: Of 129 BRCA1/2 positive patients identified by a community-based cancer genetics program outside Philadelphia from 1998 to 2008, 44 were excluded due to personal history of ovarian cancer, loss of follow-up, male gender, or deceased status. The 85 remaining patients were asked to complete a questionnaire addressing: age at diagnosis, ethnicity, religion, parity, education level, marital status, occupation, number of first degree relatives with breast or ovarian cancer, personal history of breast cancer, and use of oral contraceptives, tobacco, and alcohol. A chart review was performed on all responders.Results: Forty-nine patients (58%) completed the questionnaire. Of these, 68% (34/49) had RRS. Of those who did not have RRS, 63% (10/15) stated they definitely plan for RRS in the future. More than half of the women planning RRS in the future (6/10) were younger than 30 years old. Therefore, of all responders, 90% (44/49) stated they had or definitely plan to have RRS. The mean age of women with RRS versus those without was 43.9 and 35.6 years, respectively (p=.0102). Women age 40-64 had the highest rate of RRS (26/34; 84%; p=0.004). Most women (88%) with RRS had children (30/34; p=0.0493). Sixty-five percent (32/49) of women responders were college graduates; 24% were high school graduates (12/49). Of women who had RRS, 68% were college graduates. College graduates age > 40 were the group most likely to have RRS (17/18; 94%; p= .00029). Only 63% of high school graduates age > 40 (5/8; p=1.0) had RRS. Eight-five percent (11/13) of Ashkenazi Jewish women had RRS versus 67% (18/27) of non-Jewish Caucasian women. This was not statistically significant (p=0.2925). There was also no statistical difference for women choosing RRS with respect to occupation, birth control pill use, history of breast cancer, or family history of breast or ovarian cancer. Only 3/49 smoked cigarettes (>more than 1 pack per week) and none drank alcohol (>1 drink/day).Discussion: Women who presented to this community based genetics program had a high rate of RRS, were likely to be college educated, non-smokers, and non-drinkers. Age older than 40, completion of child bearing, and attainment of a college degree were the most significant factors associated with BRCA 1/2 mutation carriers having RRS. Further studies should explore barriers to genetic testing services, as well as evaluate reasons why BRCA1/2 mutation carriers decline RRS.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4076.

Transmutation of 239Pu and other nuclides using spallation neutrons produced by relativistic protons reacting with massive U- and Pb-targets

Experimental studies on the transmutation of some long-lived radioactive waste nuclei, such as 129I, 237Np, and 239Pu, as well as on natural uranium and lanthanum were carried out at the Synchrophastron of the Laboratory for High Energies at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. The radioactive targets (I, Np and Pu) were contained in weld-sealed aluminium holders produced by the Institute of Physics and Power Engineering, Obninsk, Russia. Spallation neutrons were produced by relativistic protons with energies in the range of 0.5 GeV≤E p≤1.5 GeV interacting with 20 cm long uranium or lead target stacks. The metallic targets were surrounded by 6 cm thick paraffin moderators. The uranium and lanthanum samples were positioned on the outside of the moderator surface and typically contained approximately 0.5 to 1.0 gram of uranium or lanthanum. The highest fluence of spallation neutrons was observed in the region of 5 to 10 cm downstream the entrance of the primary beam into the metallic target, rather independent of the target material or the proton energy. The results obtained by nuclear chemistry methods were supplemented by SSNTD (Solid State Nuclear Track Detector) studies. Consistent and systematic results of B-values and spectral distributions for neutrons have been found. From the experimentally observed transmutation rates one can extrapolate that in a subcritical nuclear power assembly (or "energy amplifier") using a 10 mA proton beam of 1 GeV onto a Pb-target as used here, one can transmute within one month in one gram of sample about 3 mg 129I, 21 mg 237Np, 3.3 mg 238U, and 200 mg 239Pu. Rather similar results have been found by another group for 129I and 239Pu. Observations show that the transmutation rates increase almost linearly with the proton energy in the energy interval 0.5 GeV up to 7.4 GeV. These findings are largely confirmed by model calculations using the LAHET- and DCM/CEM-codes.

Thin, stubby or mushroom: spine pathology in Alzheimer's disease

Since their first description by Ramon y Cajal at the end of the 19th century, dendritic spines have been proposed as important sites of neuronal contacts and it has been suggested that changes in the activity of neurons directly affect spine morphology. In fact, since then it has been shown that about 90% of excitatory synapses end on spines. Recent data indicate that spines are highly dynamic structures and that spine shape correlates with the strength of synaptic transmission. Furthermore, several mental disorders including Alzheimer's disease (AD) are associated with spine pathology suggesting that spine alterations play a central role in mental deficits. The aim of this review is to provide an overview about the current knowledge on spine morphology and function as well as about different experimental models to analyze spine changes and dynamics. The second part concentrates on disease-relevant factors that are associated with AD and which lead to spine alterations. In particular, data that provide evidence that Abeta oligomers or fibrillar Abeta deposits influence spine morphology and function will be presented and the contribution of tau pathology will be discussed. The review ends with the discussion of potential mechanisms how disease-relevant factors influence dendritic spines and whether and how spine changes could be therapeutically suppressed or reversed.

Multicenter, randomized study of the efficacy and safety of intravenous iclaprim in complicated skin and skin structure infections

Iclaprim is a novel antibacterial agent that is currently in development for the treatment of complicated skin and skin structure infections (cSSSI). Iclaprim specifically and selectively inhibits bacterial dihydrofolate reductase, a critical enzyme in the bacterial folate pathway, and exhibits an extended spectrum of activity against various resistant pathogens, including methicillin (meticillin)-resistant Staphylococcus aureus (MRSA). The objective of this randomized, double-blind phase II study was to compare the efficacy and safety of iclaprim to those of vancomycin in patients with cSSSI. Patients were randomized to receive 0.8 mg iclaprim/kg of body weight, 1.6 mg/kg iclaprim, or 1 g vancomycin twice a day for 10 days. Clinical cure rates for the 0.8- and 1.6-mg/kg-iclaprim treatment groups were comparable to that for the vancomycin treatment group (26/28 patients [92.9%], 28/31 patients [90.3%], and 26/28 patients [92.9%], respectively). Iclaprim also showed high microbiological eradication rates. Iclaprim exhibited an eradication rate of 80% and 72% versus 59% observed with vancomycin for S. aureus, the pathogen most frequently isolated at baseline. Five MRSA cases were observed, four in the 0.8-mg/kg-iclaprim arm and one in the vancomycin arm, and all were both clinically and microbiologically cured. Iclaprim exhibited a safety profile similar to that of vancomycin, an established drug for the treatment of cSSSI. Results from this study indicate that iclaprim is a promising new therapy for the treatment of cSSSI, in particular those caused by S. aureus, including MRSA.

The effect of fluid deprivation, antidiuretic hormone and forced fluid intake on 51-Cr-EDTA clearance

The effect of fluid deprivation, antidiuretic hormone (DDAVP) and forced fluid intake on glomerular filtration rate (GFR) was studied in 41 healthy males by determining 51-Cr-EDTA clearance after a single bolus injection. GFR was the same on forced and on free fluid intake. A small, clinically insignificant decrease in GFR (-6.5%), compared to values on free fluid intake, was registered during the periods of fluid deprivation plus DDAVP. There seem to be no objections to combining a clearance study with a concentrating ability test when screening groups of subjects with normal or near normal GFR.

Studies on kidney function in subjects exposed to organic solvents. IV. Effect on 51-Cr-EDTA clearance

Glomerular filtration rate (GFR) was studied by measuring the 51-Cr-EDTA clearance with single bolus injection technique in 107 men exposed to styrene, toluene or toluene and xylene in their professions and in 48 non-exposed male controls. The clearance values of the controls were significantly related both to body surface area (BSA) and age. These relations were used to calculate expected clearances for the exposed subjects. The clearances of the exposed subjects were on an average 3.8% higher than expected, according to BSA and age in this group. This divergence was not significant. Thus, no reduction in GFR was found in the subjects exposed to organic solvents.

Attachment ofMAL32-encoded maltase on the outside of yeast cells improves maltotriose utilization

The fermentation of maltotriose, the second most abundant fermentable sugar in wort, is often incomplete during high-gravity brewing. Poor maltotriose consumption is due to environmental stress conditions during high-gravity fermentation and especially to a low uptake of this sugar by some industrial strains. In this study we investigated whether the use of strains with an alpha-glucosidase attached to the outside of the cell might be a possible way to reduce residual maltotriose. To this end, the N-terminal leader sequence of Kre1 and the carboxy-terminal anchoring domain of either Cwp2 or Flo1 were used to target maltase encoded by MAL32 to the cell surface. We showed that Mal32 displayed on the cell surface of Saccharomyces cerevisiae laboratory strains was capable of hydrolysis of alpha-1,4-linkages, and that it increased the ability of a strain lacking a functional maltose permease to grow on maltotriose. Moreover, the enzyme was also expressed and found to be active in an industrial strain. These data show that expressing a suitable maltase on the cell surface might provide a means of modifying yeast for more complete maltotriose utilization in brewing and other fermentation applications.

Prognostic value of N-terminal pro-B-type natriuretic peptide for conservatively and surgically treated patients with aortic valve stenosis

OBJECTIVE

To evaluate the prognostic value of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with aortic stenosis being treated conservatively or undergoing aortic valve replacement (AVR).

METHODS

159 patients were followed up for a median of 902 days. 102 patients underwent AVR and 57 were treated conservatively. NT-proBNP at baseline was raised in association with the degree of severity and of functional status.

RESULTS

During follow up 21 patients (13%) died of cardiac causes or required rehospitalisation for decompensated heart failure. NT-proBNP at baseline was higher in patients with an adverse outcome than in event-free survivors (median 623 (interquartile range 204-1854) pg/ml v 1054 (687-2960) pg/ml, p = 0.028). This difference was even more obvious in conservatively treated patients (331 (129-881) pg/ml v 1102 (796-2960) pg/ml, p = 0.002). Baseline NT-proBNP independently predicted an adverse outcome in the entire study group and in particular in conservatively treated patients (area under the curve (AUC) = 0.65, p = 0.028 and AUC = 0.82, p = 0.002, respectively) but not in patients undergoing AVR (AUC = 0.544). At a cut-off value of 640 pg/ml, baseline NT-proBNP was discriminative for an adverse outcome.

CONCLUSION

NT-proBNP concentration is related to severity of aortic stenosis and provides independent prognostic information for an adverse outcome. However, this predictive value is limited to conservatively treated patients. Thus, the data suggest that assessing NT-proBNP may have incremental value for selecting the optimal timing of valve replacement.

Detection of spallation neutrons and protons using the (nat)Cd activation technique in transmutation experiments at Dubna

Various spallation sources have been used to transmute long-lived radioactive waste, mostly making use of the wide energy neutron fluence. In addition to neutrons, a large number of protons and gamma rays are also emitted from these sources. In this paper (nat)Cd is proved to be a useful activation detector for determining both thermal-epithermal neutron as well as secondary proton fluences. The fluences measured with (nat)Cd compared with other experimental data and calculations of DCM-DEM code were found to be in reasonable agreement. An accumulation of thermal-epithermal neutrons around the center of the target (i.e. after approx. 10 cm) and of secondary protons towards the end of the target is observed.

Nickel release, a possible indicator for the duration of antiplatelet treatment, from a nickel cardiac device in vivo: a study in patients with atrial septal defects implanted with an Amplatzer occl

The present study was undertaken to evaluate the safety and release of nickel after implantation of a nickel device (Amplatzer occluder) in patients with an atrial septal defect (ASD) receiving antiplatelet therapy.

METHODS

Blood and urine samples were obtained from 24 patients with ASD before occluder implantation (baseline) and during a 12-month post closure period. Antiplatelet drugs were administered for the initial 6-month period post implantation. The nickel content in the specimens was determined using electrothermal atomic absorption spectroscopy. The clinical, sonographic and magnetic resonance imaging follow-ups were carried out 1 week, 1 month, 6 months and 12 months post implantation.

RESULTS

Mean baseline concentrations of nickel in serum and urine were within normal range with values of 0.6 +/- 0.2 microg/l and 3.1 +/- 1.2 microg/l, respectively. During the 6-week post closure period, the time needed for the formation of neointima on the surface of the graft, nickel levels in serum increased up to 5-fold (p < 0.01 versus baseline). Mean concentrations in serum and urine returned to baseline levels within 4-6 months post implantation. All patients showed satisfactory clinical improvements and there was no sonographic evidence of complications.

CONCLUSIONS

The initial dissolution of nickel from the Amplatzer occluder is not a specific cardiovascular risk and is temporarily linked to the formation of the non-thrombogenic neointima on the surface of the graft. The antiplatelet drug regimen used (300 mg aspirin + 75 mg clopidogrel daily for 3 months in the initial phase and 100 mg aspirin daily for a further 3 months) appears to cover the period of neointima formation on the nickel device when nickel levels are significantly elevated. However, further studies in a larger number of patients and over a period greater than 12 months are needed to confirm the validity of these conclusions and to formulate definitive recommendations on the duration of the antiplatelet treatment.

Cytoskeletal mechanisms of neuronal morphogenesis

The cytoskeleton is the major intracellular structure that determines the morphology of a neuron. Thus, mechanisms that ensure a precisely regulated assembly of cytoskeletal elements in time and space have an important role in the development from a morphologically simple neuronal precursor cell to a complex polarized neuron that can establish contacts to several hundreds of other cells. Here, cytoskeletal mechanisms that underlie the formation of neurites, directed elongation and stabilization of neuronal processes are summarized. It has become evident that different cytoskeletal elements are highly crosslinked with each other by several classes of specific linker proteins. Of these, microtubule-associated proteins (MAPs) appear to have an important role in connecting the microtubule skeleton to other cytoskeletal filaments and plasma membrane components during neuronal morphogenesis. Future experiments will have to elucidate the function and the regulation of the neuronal cytoskeleton in an authentic nervous system environment during development. Recent approaches are discussed at the end of this article.