Prevention of allergies and infections by minimally processed milk in infants-The MARTHA feasibility and safety trial.

BACKGROUND: Consumption of raw cow's milk has repeatedly been shown to protect from asthma, allergies, and respiratory infections. As raw milk bears potential health hazards, it cannot be recommended for prevention. Therefore, we performed an intervention study with microbially safe but otherwise minimally processed cow's milk. Here we describe feasibility and safety of the trial. METHODS: The MARTHA trial (DRKS00014781) was set up as a double-blind randomized intervention in a population residing in Bavaria. Infants from 6 to 36 months of age consumed minimally processed cow's milk (intervention arm) or ultra-heat-treated (UHT) semi-skimmed milk (comparator arm). RESULTS: At the age of 6 to 12 months, 260 infants were enrolled, with 72% having a family history of atopy. The extensive screening system for milk consumption and symptoms suggestive of adverse events was well accepted with 22,988 completed weekly surveys and an average completion of 82% surveys sent out. The children consumed the study milk on average on 457 days (61% of intervention days). The intervention proved to be safe without any case of milk allergy or milk intolerance under the intervention in both arms. All 6 cases of serious adverse events were unrelated to milk. The most common reason was unscheduled hospitalization of more than 3 days. CONCLUSIONS: The intervention with minimally processed milk and the study instruments proved feasible. During the age of 6 to 36 months, there was no increased risk of milk allergy in a population with a substantial proportion of family history of atopy.

A new form of axonal pathology in a spinal model of neuromyelitis optica.

Neuromyelitis optica is a chronic neuroinflammatory disease, which primarily targets astrocytes and often results in severe axon injury of unknown mechanism. Neuromyelitis optica patients harbour autoantibodies against the astrocytic water channel protein, aquaporin-4 (AQP4-IgG), which induce complement-mediated astrocyte lysis and subsequent axon damage. Using spinal in vivo imaging in a mouse model of such astrocytopathic lesions, we explored the mechanism underlying neuromyelitis optica-related axon injury. Many axons showed a swift and morphologically distinct 'pearls-on-string' transformation also readily detectable in human neuromyelitis optica lesions, which especially affected small calibre axons independently of myelination. Functional imaging revealed that calcium homeostasis was initially preserved in this 'acute axonal beading' state, ruling out disruption of the axonal membrane, which sets this form of axon injury apart from previously described forms of traumatic and inflammatory axon damage. Morphological, pharmacological and genetic analyses showed that AQP4-IgG-induced axon injury involved osmotic stress and ionic overload, but does not appear to use canonical pathways of Wallerian-like degeneration. Subcellular analysis demonstrated remodelling of the axonal cytoskeleton in beaded axons, especially local loss of microtubules. Treatment with the microtubule stabilizer epothilone, a putative therapy approach for traumatic and degenerative axonopathies, prevented axonal beading, while destabilizing microtubules sensitized axons for beading. Our results reveal a distinct form of immune-mediated axon pathology in neuromyelitis optica that mechanistically differs from known cascades of post-traumatic and inflammatory axon loss, and suggest a new strategy for neuroprotection in neuromyelitis optica and related diseases.

Impact of Pre- and Intraoperative Factors on Endothelial Cell Density in the Early and Late Stage after Penetrating Keratoplasty. / Prä- und intraoperative Einflussgrößen auf die Endothelzellentwicklung in der Früh- und Spätphase nach perforierender Keratoplastik.

AIM: This retrospective investigated the impact of donor age, recipient age, donor endothelial cell density, vis-à-tergo, and additional intraoperative lens exchange (triple-procedure) on overall early and late phase postoperative endothelial cell density (ECD) following penetrating keratoplasty (PKP) in various diagnosis groups. PATIENTS AND METHODS: In 590 cases with diagnosed keratoconus (KC), Fuchs dystrophy (FD) and herpes simplex virus infection (HSV) who underwent PKP or triple surgery, the ECD in cells/mm2 was analysed, both preoperatively, with all-sutures-in (early postoperative stage), and after last suture removal. The factors were tested by Mann-Whitney U-test, correlation analysis and linear regression analysis. OUTCOME: Correlation analysis demonstrated a weak negative correlation between the patient's ECD and donor age (early postoperative stage: r = - 0.25, p < 0.001; after last suture removal: r = - 0.16; p = 0.003). Regression analysis revealed that donor age did not impact postoperative patient ECD. There was a weak negative correlation between postoperative ECD and recipient age (early postoperative stage: r = - 0.31, p < 0.001; after last suture removal: r = - 0.34, p < 0.001). Regression analysis confirmed the negative impact of recipient age on patient ECD (early postoperative stage: ß = - 13.2, p = 0.001; after last suture removal: ß = - 4.6, p < 0.001). Correlation analysis determined a weak positive correlation between postoperative ECD and donor endothelial cell density (early postoperative stage: r = 0.37, p < 0.001; after last suture removal: r = 0.32, p < 0.001). Regression analysis also determined that donor endothelial cell density had a positive impact on postoperative ECD following last suture removal (ß = 0.4, p < 0.001). Vis-à-tergo and additional lens exchange (triple procedure) had no significant effect on postoperative ECD (p > 0.05). This was also confirmed by the results of the regression analysis after last suture removal. CONCLUSION: Recipient age and donor endothelial cell density have a significant impact on postoperative ECD following PKP. Not all of the statistical tests proved donor age to be a significant influencing factor. Vis-à-tergo and additional lens exchange (triple procedure) had no significant effect on postoperative ECD following PKP.

Exploration of the sputum methylome and omics deconvolution by quadratic programming in molecular profiling of asthma and COPD: the road to sputum omics 2.0.

BACKGROUND: To date, most studies involving high-throughput analyses of sputum in asthma and COPD have focused on identifying transcriptomic signatures of disease. No whole-genome methylation analysis of sputum cells has been performed yet. In this context, the highly variable cellular composition of sputum has potential to confound the molecular analyses. METHODS: Whole-genome transcription (Agilent Human 4 × 44 k array) and methylation (Illumina 450 k BeadChip) analyses were performed on sputum samples of 9 asthmatics, 10 healthy and 10 COPD subjects. RNA integrity was checked by capillary electrophoresis and used to correct in silico for bias conferred by RNA degradation during biobank sample storage. Estimates of cell type-specific molecular profiles were derived via regression by quadratic programming based on sputum differential cell counts. All analyses were conducted using the open-source R/Bioconductor software framework. RESULTS: A linear regression step was found to perform well in removing RNA degradation-related bias among the main principal components of the gene expression data, increasing the number of genes detectable as differentially expressed in asthma and COPD sputa (compared to controls). We observed a strong influence of the cellular composition on the results of mixed-cell sputum analyses. Exemplarily, upregulated genes derived from mixed-cell data in asthma were dominated by genes predominantly expressed in eosinophils after deconvolution. The deconvolution, however, allowed to perform differential expression and methylation analyses on the level of individual cell types and, though we only analyzed a limited number of biological replicates, was found to provide good estimates compared to previously published data about gene expression in lung eosinophils in asthma. Analysis of the sputum methylome indicated presence of differential methylation in genomic regions of interest, e.g. mapping to a number of human leukocyte antigen (HLA) genes related to both major histocompatibility complex (MHC) class I and II molecules in asthma and COPD macrophages. Furthermore, we found the SMAD3 (SMAD family member 3) gene, among others, to lie within differentially methylated regions which has been previously reported in the context of asthma. CONCLUSIONS: In this methodology-oriented study, we show that methylation profiling can be easily integrated into sputum analysis workflows and exhibits a strong potential to contribute to the profiling and understanding of pulmonary inflammation. Wherever RNA degradation is of concern, in silico correction can be effective in improving both sensitivity and specificity of downstream analyses. We suggest that deconvolution methods should be integrated in sputum omics analysis workflows whenever possible in order to facilitate the unbiased discovery and interpretation of molecular patterns of inflammation.

The intestinal microbiota determines the colitis-inducing potential of T-bet-deficient Th cells in mice.

Conflicting evidence has been provided as to whether induction of intestinal inflammation by adoptive transfer of naïve T cells into Rag-/- mice requires expression of the transcription factor T-bet by the T cells. Here, we formally show that the intestinal microbiota composition of the Rag-/- recipient determines whether or not T-bet-deficient Th cells can induce colitis and we have resolved the differences of the two microbiomes, permissive or non-permissive to T-bet-independent colitis. Our data highlight the dominance of the microbiota over particular T cell differentiation programs in the pathogenesis of chronic intestinal inflammation.

EGAD: ultra-fast functional analysis of gene networks.

Summary: Evaluating gene networks with respect to known biology is a common task but often a computationally costly one. Many computational experiments are difficult to apply exhaustively in network analysis due to run-times. To permit high-throughput analysis of gene networks, we have implemented a set of very efficient tools to calculate functional properties in networks based on guilt-by-association methods. ( xtending ' uilt-by- ssociation' by egree) allows gene networks to be evaluated with respect to hundreds or thousands of gene sets. The methods predict novel members of gene groups, assess how well a gene network groups known sets of genes, and determines the degree to which generic predictions drive performance. By allowing fast evaluations, whether of random sets or real functional ones, provides the user with an assessment of performance which can easily be used in controlled evaluations across many parameters. Availability and Implementation: The software package is freely available at https://github.com/sarbal/EGAD and implemented for use in R and Matlab. The package is also freely available under the LGPL license from the Bioconductor web site ( http://bioconductor.org ). Contact: JGillis@cshl.edu. Supplementary information: Supplementary data are available at Bioinformatics online.

Selective targeting of pro-inflammatory Th1 cells by microRNA-148a-specific antagomirs in vivo.

In T lymphocytes, expression of miR-148a is induced by T-bet and Twist1, and is specific for pro-inflammatory Th1 cells. In these cells, miR-148a inhibits the expression of the pro-apoptotic protein Bim and promotes their survival. Here we use sequence-specific cholesterol-modified oligonucleotides against miR-148a (antagomir-148a) for the selective elimination of pro-inflammatory Th1 cells in vivo. In the murine model of transfer colitis, antagomir-148a treatment reduced the number of pro-inflammatory Th1 cells in the colon of colitic mice by 50% and inhibited miR-148a expression by 71% in the remaining Th1 cells. Expression of Bim protein in colonic Th1 cells was increased. Antagomir-148a-mediated reduction of Th1 cells resulted in a significant amelioration of colitis. The effect of antagomir-148a was selective for chronic inflammation. Antigen-specific memory Th cells that were generated by an acute immune reaction to nitrophenylacetyl-coupled chicken gamma globulin (NP-CGG) were not affected by treatment with antagomir-148a, both during the effector and the memory phase. In addition, antibody titers to NP-CGG were not altered. Thus, antagomir-148a might qualify as an effective drug to selectively deplete pro-inflammatory Th1 cells of chronic inflammation without affecting the protective immunological memory.

Identification of Novel Nuclear Factor of Activated T Cell (NFAT)-associated Proteins in T Cells.

Transcription factors of the nuclear factor of activated T cell (NFAT) family are essential for antigen-specific T cell activation and differentiation. Their cooperative DNA binding with other transcription factors, such as AP1 proteins (FOS, JUN, and JUNB), FOXP3, IRFs, and EGR1, dictates the gene regulatory action of NFATs. To identify as yet unknown interaction partners of NFAT, we purified biotin-tagged NFATc1/αA, NFATc1/ßC, and NFATc2/C protein complexes and analyzed their components by stable isotope labeling by amino acids in cell culture-based mass spectrometry. We revealed more than 170 NFAT-associated proteins, half of which are involved in transcriptional regulation. Among them are many hitherto unknown interaction partners of NFATc1 and NFATc2 in T cells, such as Raptor, CHEK1, CREB1, RUNX1, SATB1, Ikaros, and Helios. The association of NFATc2 with several other transcription factors is DNA-dependent, indicating cooperative DNA binding. Moreover, our computational analysis discovered that binding motifs for RUNX and CREB1 are found preferentially in the direct vicinity of NFAT-binding motifs and in a distinct orientation to them. Furthermore, we provide evidence that mTOR and CHEK1 kinase activity influence NFAT's transcriptional potency. Finally, our dataset of NFAT-associated proteins provides a good basis to further study NFAT's diverse functions and how these are modulated due to the interplay of multiple interaction partners.

Ascl1/Mash1 promotes brain oligodendrogenesis during myelination and remyelination.

Oligodendrocytes are the myelin-forming cells of the CNS. They differentiate from oligodendrocyte precursor cells (OPCs) that are produced from progenitors throughout life but more actively during the neonatal period and in response to demyelinating insults. An accurate regulation of oligodendrogenesis is required to generate oligodendrocytes during these developmental or repair processes. We hypothesized that this regulation implicates transcription factors, which are expressed by OPCs and/or their progenitors. Ascl1/Mash1 is a proneural transcription factor previously implicated in embryonic oligodendrogenesis and operating in genetic interaction with Olig2, an essential transcriptional regulator in oligodendrocyte development. Herein, we have investigated the contribution of Ascl1 to oligodendrocyte development and remyelination in the postnatal cortex. During the neonatal period, Ascl1 expression was detected in progenitors of the cortical subventricular zone and in cortical OPCs. Different genetic approaches to delete Ascl1 in cortical progenitors or OPCs reduced neonatal oligodendrogenesis, showing that Ascl1 positively regulated both OPC specification from subventricular zone progenitors as well as the balance between OPC differentiation and proliferation. Examination of remyelination processes, both in the mouse model for focal demyelination of the corpus callosum and in multiple sclerosis lesions in humans, indicated that Ascl1 activity was upregulated along with increased oligodendrogenesis observed in remyelinating lesions. Additional genetic evidence indicated that remyelinating oligodendrocytes derived from Ascl1(+) progenitors/OPCs and that Ascl1 was required for proper remyelination. Together, our results show that Ascl1 function modulates multiple steps of OPC development in the postnatal brain and in response to demyelinating insults.

Evaluation of hop test movement quality to enhance return to sport testing. A cross-sectional study.

Introduction: Return to Sport tests with functional hop tests are often used to decide when a person is ready to return to sport after an anterior cruciate ligament (ACL) injury. Poor movement quality, such as knee valgus, hip adduction and hip internal rotation is considered a risk factor for ACL injury. However, it is unclear whether existing tests adequately cover the aspect of movement quality. This study aims to investigate whether there is a relationship between the calculated limb symmetry index (LSI) of hop tests as an indication of performance and the total score of the "Quality First" assessment (movement quality). The second aim is to examine the reliability of the newly developed "Quality First" assessment for evaluating movement quality in hop tests. Methods: The cross-sectional study recruited 34 patients with an ACL reconstruction. The vertical hop, single-leg hop for distance, and side hop tests were performed and recorded. The video recordings were assessed using the "Quality First" assessment. The Spearman correlation coefficient was calculated using the LSI and the "Quality First" total score. Intraclass correlation coefficients (ICC) and standard error of measurements (SEM) were used to calculate intra- and interrater reliability. In addition, the minimal detectable change (MDC) was determined. Results: The correlation test between the LSI and the "Quality First" total score showed no correlation for all three jumps (r = -0.1-0.02/p-value = 0.65-0.93). The interrater reliability of the "Quality First" assessment showed fair to good reliability (ICC2: 0.45-0.60), with SEM ranging from 1.46 to 1.73 and the MDC from 4.06 to 4.8. Intrarater reliability was good to excellent (ICC3: 0.73-0.85), with SEM values ranging from 0.89 to 1.09 and the MDC from 2.47 to 3.01. Conclusion: The quality of movement, measured with the "Quality First" assessment, indicated no correlation with the calculated LSI from jump performance, therefore movement quality should also be examined in Return to Sport tests. The "Quality First" assessment shows fair to good reliability when used by different raters. When used multiple times by the same rater, the assessment has good to excellent reliability.

Mechanical versus biological mitral valve replacement: Insights from propensity score matching on survival and reoperation rates.

OBJECTIVES: Patients with symptomatic mitral valve disease unsuitable for repair can be sufficiently treated with surgical mitral valve replacement. The decision between biological and mechanical mitral valve replacement can be difficult, especially due to the question of the lesser of 2 evils: anticoagulation versus reoperation. METHODS: This single-center, retrospective study included all patients undergoing mitral valve replacement between 2001 and 2020. Thirty-day mortality and periprocedural complications were analyzed. Propensity score matching adjusted for age, gender, weight, height, endocarditis, diabetes, hypertension, peripheral arterial occlusive disease, atrial fibrillation, chronic kidney disease, cancer, and history of neurological disorders was performed. After propensity score matching, survival and cumulative incidence of reoperation at time of follow-up were analyzed. RESULTS: The study included 2027 patients in 2 main groups: 1658 patients with biological mitral valve replacement and 369 patients with mechanical mitral valve replacement; 51.2% were male. Age at surgery was 65.9 ± 12.9 years. Median follow-up time was 6.83 years (interquartile range, 1.11-10.61 years). Concomitant procedures were performed in 1467 cases (72.4%). Propensity score matching yielded comparable groups of 339 pairs. Both groups showed comparable survival (P = .203). Survival after mechanical mitral valve replacement and biological mitral valve replacement was comparable for all analyzed time points over the course of 20 years. Patients with mechanical mitral valve replacement showed a significantly lower cumulative incidence for reoperation (20 years: 15% vs 59%, P < .001). CONCLUSIONS: Follow-up of 20 years at a high-volume center demonstrates comparable survival after mechanical or biological mitral valve replacement, whereas reoperation rates are significantly lower after mechanical mitral valve replacement.

Biocatalytic Heteroaromatic Amide Formation in Water Enabled by a Catalytic Tetrad and Two Access Tunnels.

The amide moiety belongs to the most common motives in pharmaceutical chemistry, present in many prescribed small-molecule pharmaceuticals. Methods for its manufacture are still in high demand, especially using water/buffer as a solvent and avoiding stoichiometric amounts of activation reagents. Herein, we identified from a library of lipases/esterases/acyltransferases and variants thereof a lipase originating from Sphingomonas sp. HXN-200 (SpL) able to form amides in aqueous solution starting from a broad scope of sterically demanding heteroaromatic ethyl esters as well as aliphatic amines, reaching isolated yields up to 99% on preparative scale and space time yields of up to 864 g L-1 d-1; thus, in selected cases, the amide was formed within minutes. The enzyme features an aspartate next to the canonical serine of the catalytic triad, which was essential for amide formation. Furthermore, the enzyme structure revealed two tunnels to the active site, presumably one for the ester and one for the amine, which permit the bringing together of the sterically demanding heteroaromatic esters and the amine in the active site. This work shows that biocatalytic amide formation starting from various five- and six-membered heteroaromatic ethyl esters in the buffer can serve as a platform for preparative amide synthesis.

Content validity, interpretability, and internal consistency of the "Quality First" assessment to evaluate movement quality in hop tests following ACL rehabilitation. A cross-sectional study.

Introduction: Current approaches fail to adequately identify sport readiness after anterior cruciate ligament (ACL) rehabilitation. Altered landing biomechanics after ACL reconstruction are associated with increased risk of a noncontact ACL reinjury. There is a lack of objective factors to screen for deficient movement patterns. Therefore, the aim of this study was to investigate content validity, interpretability, and internal consistency for the newly developed "Quality First" assessment to evaluate movement quality during hop tests in patients after ACL rehabilitation. Method: Participants in this cross-sectional study were recruited in collaboration with the Altius Swiss Sportmed Center in Rheinfelden, Switzerland. After a successful ACL reconstruction, the movement quality of 50 hop test batteries was evaluated between 6 and 24 months postoperatively with the "Quality First" assessment. Content validity was assessed from the perspective of professionals. To check the interpretability, classical test theory was employed. Cronbach's α was calculated to evaluate internal consistency. Results: Content validity resulted in the inclusion of three different hop tests (single-leg hop for distance, vertical hop, and side hop). The "Quality First" assessment is enabled to evaluate movement quality in the sagittal, vertical, and the transversal plane. After the exclusion process, the "Quality First" assessment was free from floor and ceiling effects and obtained a sufficient Cronbach's α. The final version consists of 15 items, rated on a 4-point scale. Discussion: By means of further validations, the "Quality First" assessment could offer a possibility to evaluate movement quality after ACL rehabilitation during hop tests.

Learn to Turn: Does Spotting Foster Skill Acquisition in Pirouettes?

Purpose: The spotting technique (i.e., independent head from torso movement) has been revealed as the single feature that differentiates highly skilled from less-skilled dancers. In the current intervention study, the potential of a specific spotting training in novice dancers for learning double pirouettes was tested. Method: Novice dancers trained pirouettes in an experimental group and an active control group over a period of eight weeks by receiving either specific spotting instructions or technical instructions only. Pirouette performance was examined in a pretest, and a one-week-delayed retention test. In a further control test, effects of explicitly instructing how to perform the pirouettes (i.e., either with or without spotting) were investigated. Results: Different than expected, in the retention test, only few participants from the experimental group showed the spotting technique. Moreover, the spotting group did not perform better than the control group. Rather, the balance measure revealed that, while the control group improved over learning, the experimental group remained at the baseline values and showed a slight advantage for orientation only. In the control test, all groups showed inferior performance as compared to the retention test. Conclusion: In sum, the current findings show that-at least for beginners-the spotting technique is not suitable to be implemented in applied training settings. Moreover, in line with the expert performance approach, this study suggests to investigate the implementation of expert skills in applied training routines experimentally.

Ganglioside lipidomics of CNS myelination using direct infusion shotgun mass spectrometry.

Gangliosides are present and concentrated in axons and implicated in axon-myelin interactions, but how ganglioside composition changes during myelin formation is not known. Here, we present a direct infusion (shotgun) lipidomics method to analyze gangliosides in small amounts of tissue reproducibly and with high sensitivity. We resolve the mouse ganglioside lipidome during development and adulthood and determine the ganglioside content of mice lacking the St3gal5 and B4galnt1 genes that synthesize most ganglioside species. Our results reveal substantial changes in the ganglioside lipidome during the formation of myelinated nerve fibers. In sum, we provide insights into the CNS ganglioside lipidome with a quantitative and sensitive mass spectrometry method. Since this method is compatible with global lipidomic profiling, it will provide insights into ganglioside function in physiology and pathology.

Increased HERV-K(HML-2) Transcript Levels Correlate with Clinical Parameters of Liver Damage in Hepatitis C Patients.

Chronic hepatitis C virus (HCV) infection is closely associated with a plethora of diseases, including cancers and autoimmune disorders. However, the distinct triggers and cellular networks leading to such HCV-derived diseases are poorly understood. Around 8% of the human genome consists of human endogenous retroviruses. They are usually silenced but can be reactivated by environmental conditions, including viral infections. Our current understanding indicates that the activation of one specific family-namely, HERV-K(HML-2)-is linked to distinct pathologies, including cancer and autoimmunity. In this study, we analyzed the transcription levels of HERV-K(HML-2) in 42 HCV-infected patients receiving direct-acting antiviral therapies. Samples from the start of treatment until 12 weeks post-treatment were investigated. Our results show increased HERV-K(HML-2) transcript levels in patients with HCV-derived liver cirrhosis throughout the observation period. Several clinical parameters specifying poor liver function are positively correlated with HERV-K(HML-2) expression. Of note, patients without a sustained viral clearance showed a drastic increase in HERV-K(HML-2) transcript levels. Together, our data suggest that increased HERV-K(HML-2) expression is correlated with reduced liver function as well as therapy success in HCV-infected patients.

RNA Structures and Their Role in Selective Genome Packaging.

To generate infectious viral particles, viruses must specifically select their genomic RNA from milieu that contains a complex mixture of cellular or non-genomic viral RNAs. In this review, we focus on the role of viral encoded RNA structures in genome packaging. We first discuss how packaging signals are constructed from local and long-range base pairings within viral genomes, as well as inter-molecular interactions between viral and host RNAs. Then, how genome packaging is regulated by the biophysical properties of RNA. Finally, we examine the impact of RNA packaging signals on viral evolution.

A Conserved uORF Regulates APOBEC3G Translation and Is Targeted by HIV-1 Vif Protein to Repress the Antiviral Factor.

The HIV-1 Vif protein is essential for viral fitness and pathogenicity. Vif decreases expression of cellular restriction factors APOBEC3G (A3G), A3F, A3D and A3H, which inhibit HIV-1 replication by inducing hypermutation during reverse transcription. Vif counteracts A3G at several levels (transcription, translation, and protein degradation) that altogether reduce the levels of A3G in cells and prevent its incorporation into viral particles. How Vif affects A3G translation remains unclear. Here, we uncovered the importance of a short conserved uORF (upstream ORF) located within two critical stem-loop structures of the 5' untranslated region (5'-UTR) of A3G mRNA for this process. A3G translation occurs through a combination of leaky scanning and translation re-initiation and the presence of an intact uORF decreases the extent of global A3G translation under normal conditions. Interestingly, the uORF is also absolutely required for Vif-mediated translation inhibition and redirection of A3G mRNA into stress granules. Overall, we discovered that A3G translation is regulated by a small uORF conserved in the human population and that Vif uses this specific feature to repress its translation.

Acoustic-induced motion of the bushcricket (Mecopoda elongata, Tettigoniidae) tympanum.

Bushcrickets have a tonotopically organised hearing organ, the so-called crista acustica, in the tibia of the forelegs. This organ responds to a frequency range of about 5-80 kHz and lies behind the anterior tympanum on top of a trachea branch. We analyzed the sound-induced vibration pattern of the anterior tympanum, using a Laser-Doppler-Vibrometer Scanning microscope system, in order to identify frequency-dependent amplitude and phase of displacement. The vibration pattern evoked by a frequency sweep (4-79 kHz) showed an amplitude maximum which would correspond to the resonance frequency of an open tube system. At higher frequencies of about 30 kHz a difference in the amplitude and phase response between the distal and the proximal part of the tympanum was detected. The inner plate of the tympanum starts to wobble at this frequency. This higher mode in the motion pattern is not explained by purely acoustic characteristics of the tracheal space below the tympanum but may depend on the mechanical impedance of the tympanum plate. In accordance with a previous hypothesis, the tympanum moves over the whole tested frequency range in the dorso-ventral direction like a hinged flap with the largest displacement in its ventral part and no higher modes of vibration.

Discrete populations of isotype-switched memory B lymphocytes are maintained in murine spleen and bone marrow.

At present, it is not clear how memory B lymphocytes are maintained over time, and whether only as circulating cells or also residing in particular tissues. Here we describe distinct populations of isotype-switched memory B lymphocytes (Bsm) of murine spleen and bone marrow, identified according to individual transcriptional signature and B cell receptor repertoire. A population of marginal zone-like cells is located exclusively in the spleen, while a population of quiescent Bsm is found only in the bone marrow. Three further resident populations, present in spleen and bone marrow, represent transitional and follicular B cells and B1 cells, respectively. A population representing 10-20% of spleen and bone marrow memory B cells is the only one qualifying as circulating. In the bone marrow, all cells individually dock onto VCAM1+ stromal cells and, reminiscent of resident memory T and plasma cells, are void of activation, proliferation and mobility.