The properties of the complexes are evaluated as a function of the donor ligands, and correlations are drawn among electrochemical, optical, and theoretical data. Special focus has been put on the spectroelectrochemical investigation of the complexes featuring sulfonyl‐substituted phenylendiamide ligands, which show redox‐induced linkage isomerism upon oxidation. Time‐dependent density functional theory (TD‐DFT) as well as electron flux density analysis have been employed to rationalize the optical spectra of the complexes and their reactivity. Compound 1 ([(pimp)Pt(Q2−)] with Q2−=3,5‐di‐tert‐butylcatecholate) was shown to be an efficient photosensitizer for molecular oxygen and was subsequently employed in photochemical cross‐dehydrogenative coupling (CDC) reactions. The results thus display new avenues for donor–acceptor systems, including their role as photocatalysts for organic transformations, and the possibility to introduce redox‐induced linkage isomerism in these compounds through the use of sulfonamide substituents on the donor ligands.Asymmetric platinum donor–acceptor complexes [(pimp)Pt(Q Outcomes of ligand design: A series of platinum‐based donor–acceptor complexes is presented. The effect of the donor ligands on the frontier orbitals, redox potentials, redox‐induced isomerism, and photocatalysis is probe. Figure As donor ligands, catecholate/semiquinone/quinone ligands have been well‐established due to their strong donor properties and well‐defined redox behavior.o‐bis(sulfonamide) ligands in this work. Although this ligand class was described for the first time more than half a century ago,Special emphasis is put on the redox‐induced reactivity of the systems featuring Perutz and co‐workers studied rhodium(III) complexes with symmetrically and asymmetrically sulfonylated bis(amido)benzenes for transfer hydrogenation, showing the catalytic applications of these ligands.1–5 were prepared by following a previously established route (Scheme 6) with (dmso)2PtCl2 yielded the platinum dichloride complex 7 in good yield. In the presence of triethylamine, the respective quinoid ligands H2Qx were deprotonated under inert conditions in acetonitrile to give the title complexes in low to acceptable yields, as shown in Scheme 1H‐ and 13C NMR spectroscopy, mass spectrometry, and elemental analysis. All complexes are stable towards air and moisture in the solid state and in solution and can be stored for several months without detectable decomposition.Complexes 1 and 5, two regioisomers can be formed; however, only one isomer was isolated in contrast to previous studies.5, even four possible isomers are conceivable, if the position of the methylsulfonyl group relative to the plane spanned by the two binding pockets and the platinum center is taken into account. However, the barrier for the rotation is probably so low that the isomers interconvert too quickly at room temperature. A systematic screening of various reaction conditions  did not result in the formation of the other regioisomer or a mixture of both isomers. This is not observed for the strongly related pap (phenylazopyridine) complexes of platinum and palladium, which we have reported on earlier.For complexes trans‐influence of the pyridine and imino fragment are compared. From the crystal structure of (pimp)PtCl2 (7), we can see that the platinum–chloride bond in the trans‐position to the imino function is slightly elongated compared with the platinum–chloride bond in the trans‐position to the pyridine. Assuming that the imino function is an overall stronger donor than the pyridyl fragment, the first substitution is favored here. The aminosulfonyl function is more acidic and thus will likely coordinate first, which would explain the stereochemistry, with the amidosulfonyl function trans to the imino group, resulting in complex 5. The same argument can be used for complex 1, just that the difference in acidity for the hydroxy groups is less pronounced.This result is quite surprising; however, it may be partly explained, if the This finding is reproduced by DFT calculations, which predict the experimentally isolated isomer to be 0.2 eV lower in energy for pimp and thus to be thermodynamically more stable. This is in contrast to an energy difference of 0.02 eV for the pap derivatives.1 and 5. The single crystals were obtained by either vapor diffusion or evaporation of the solvent . All complexes display a distorted square planar geometry, as expected for diamagnetic platinum(II) metal centers. Compounds 1, 3, and 6 crystallize in the monoclinic P21/c space group, whereas 2 crystallizes in the monoclinic P21/n space group and 4 and 5 both crystallize in the triclinic space group P1‾.Additionally, all complexes and precursors were characterized by means of single‐crystal X‐ray diffraction . For compounds 3 and 4 featuring a NSO2R donor group, we observe a deviation from coplanarity of up to 22° (designated by angle θ), and for compound 5 featuring an oxygen and nitrogen donor, we observe an intermediate deviation  for 3 and 352.7° (DFT: 350.1°) for 4. The nitrogen in the trans‐position to the imino function, however, shows a tetrahedral distortion as evidenced by an angle of 341.9° (DFT: 338.8°) for 3, 339.7° (DFT: 341.5°) for 4, and 338.6° (DFT: 343.0°) for complex 5. This is attributed to an absence of π‐bonding of the diamidosulfonyl ligands to the metal center, when compared to unsubstituted diamidobenzenes, because similar deviations are observed for platinum(II) and rhodium(III) complexes with symmetric co‐ligands.4 shows almost the same deviations as the tosyl groups in 3.The nitrogen donors of the diamidosulfonyl ligands in complexes 1–5 show at least one reversible oxidation and one reversible reduction in a 0.1 m NBu4PF6 dichloromethane solution  centered on the pimp ligand, which may be formally reduced twice, with the formal second reduction shifted outside of the solvent window owing to the strong donation of the catecholato ligand. Interestingly, complex 1 is the only one in the series that exhibits a significant shift in the reduction potential. The redox processes are exemplified for 1 in Scheme 2–5; the second reduction was not always observed under the measurement conditions.Cyclic voltammetry reveals that complexes 2 shows two additional redox processes (oxidation and reduction), which are completely irreversible and likely result in a decomposition of the compound. The second reduction for 2 is probably irreversible due to the imine proton, considering that the second reduction on isolobal azo‐functions is often reversible. The oxidation for all compounds likely takes place on the donor ligand, which is reflected in the fact that the oxidation potentials are dependent on the nature of the donor ligand. For complexes 3–5 a second oxidation is observed, which exhibits a certain degree of reversibility. The processes do not become more reversible at faster scan rates . This subset of the investigation also nicely demonstrates the tunability of the oxidation potential by variation of either donor atoms (3 and 4 versus 5) or the substitution pattern on the nitrogen atom (3 versus 4) for the investigated series.Complex tBu2−<QNO2−<QCl2−<QTol2−<QMs2−].The “electrochemical” HOMO–LUMO gaps of the complexes correlate almost perfectly with the calculated HOMO–LUMO gaps (B3LYP/def2‐TZVP), owing to the strong localization of the HOMO on the donor ligand and the LUMO on the acceptor ligand  cell was employed. Because the CV measurements already showed that the higher oxidation states of the compounds likely show follow‐up reactions complicating the electrochemical response, we concentrated on the first oxidation and the first reduction. Early in the investigation we observed a decay in the absorption bands when measuring the spectrum in the OTTLE cell without applying a current. We witnessed a rather quick reaction/decomposition with electromagnetic radiation in the mid‐UV range. Upon removing this part of the spectrum (200–300 nm) by using an appropriate filter, we did not observe any change of the spectrum during a simple absorption measurement in the OTTLE cell. The quantitative UV/Vis/NIR measurements in a standard cuvette did not parallel these observations. If the mid‐UV range is used during the spectroelectrochemical measurement, we observe only irreversible processes, indicating a decomposition for the simultaneous application of mid‐UV radiation and a certain redox potential.1–5 are shown in Figure 1 with a strong donor ligand to 2 with the electron‐deficient tetrachlorocatecholato ligand. This decrease is matched by complexes 3 and 4 for which the donor functions change from “oxido” to amidosulfonyl. The “mixture” of both ligands  neatly lies in the middle between the two extremes. Second, we see a shift to higher energies (or shorter wavelengths) for complexes with electron‐withdrawing ligands. This nicely agrees with the intuitive assumption that we have to excite electrons from a ligand with an energetically lower‐lying HOMO and hence require more energy to do so. Again, complex 5 is in between the two extremes of 1 and 4. These broad and intense bands from roughly 540 to 700 nm can be ascribed to an LL′CT process, which is also nicely reproduced by time‐dependent density functional theory (TD‐DFT) calculations.The UV/Vis/NIR spectra for complexes 1 upon oxidation and reduction, and comparison of the spectra for 1, 1−, 1+, and 12+; for the different densities of the respective transitions, see pages S32–S37 (Supporting Information). Upon oxidation, the LL′CT band at 717 nm loses intensity and shifts to higher energies because less electron density is available on the donor ligand. Simultaneously we observe the increase of a weak band at around 1000 nm, which can be attributed to the intra‐ligand charge transfer (ILCT) process of the semiquinonato ligand. The new bands in the visible region for 1+ can be attributed to metal‐to‐ligand charge transfers (MLCTs) and π–π* transitions from the mesityl group to the donor ligand. Further oxidation to 12+ results in the loss of the NIR band around 1000 nm, and the bands in the visible region shift slightly but maintain their shape. These bands of 12+ can be assigned to MLCT processes for the now fully oxidized donor ligand.Figure The reduction takes place on the acceptor ligand: the LL′CT band again loses intensity, and a couple of new and relatively sharp bands arise in the visible/near UV region of the spectrum. These can be assigned to ILCT processes taking place on the pimp ligand. There are also minor d‐orbital contributions. This is observed for all the complexes, showing again that the reduction is taking place on the ligand, which is also reproduced by our TD‐DFT calculations .3+, 4+, and 5+, which all feature a nitrogen donor on the semiquinonato ligand, whereas complexes 1+ and 2+ with oxygen‐only donors show no absorption in this region . In contrast, complexes 1+ and 2+ show strong absorption in the visible region of the spectrum.In contrast to the absorption spectra of the native compounds, which look qualitatively similar, the spectra for the oxidized and reduced complexes differ substantially in some regards . If the spectra of all the singly oxidized compounds are compared, we observe rather intense NIR bands for complexes 1−, 2−, 3−, 4−, and 5− look relatively similar , which again indicates that the reduction steps are primarily pimp‐centered. We observe a relatively sharp double peak between 400 and 500 nm for all compounds, including the precursor 6. All compounds exhibit NIR bands that also look similar, except for 1−, for which the band is shifted significantly to higher energy. For 2−, the band is extremely weak. This indicates a varying degree of influence of the donor ligand on the reduced acceptor ligand, with the influence for 1− and 2− (with the oxygen‐bearing donor ligands) being the most pronounced.The spectra for the reduced species tBu2−<QNO2−<QCl2−<QTol2−<QMs2−].As discussed above, in these complexes, the LUMO is located on the pimp ligand and the HOMO is located on the donor ligand, and we have additionally confirmed that the low energy band can be assigned to a HOMO–LUMO transition. Thus, we can use UV/Vis/NIR spectroscopy to directly measure the HOMO–LUMO gap. The UV/Vis/NIR data can now be correlated analogously to the CV data with the DFT calculations (B3LYP/def2‐TZVP). As shown in Figure 3 showed a particular behavior during the UV/Vis/NIR spectroelectrochemical investigation. Upon oxidation of 3, a broad and very intense band at 950 nm emerged with a shoulder at around 750 nm . However, it is quite unlikely that simple rotational movements exert such a heavy influence on the absorption spectrum. The two independent isosbestic points at around 1200 and 530 nm also point to two different species that are present during the measurement. An alternative explanation would be the cleavage of one of the platinum–nitrogen bonds and coordination of the oxygen atoms of the sulfonyl groups. Such rearrangements have been proposed for rhodium complexes employing the same ligands by Perutz and co‐workers.3 to 3+, the electron density on the already electron‐poor bis(amidosulfonyl) ligand is further reduced, resulting in a weaker platinum–nitrogen bond. This possibly results in a linkage isomerization at the platinum center with one of the oxygen atoms of the sulfonyl group coordinating to it instead of the nitrogen atom  on isolated complexes in the absence of light because the complexes were not stable towards chemical oxidizing agents ([NO]BF4 or AgPF6) under an inert atmosphere .Given the different steric demands of the tosyl and mesyl substituents, it makes sense to assume that the rearrangements for complex 5 does not display this type of linkage isomerism. A tentative explanation may be the θ angle between the π‐systems of the donor and acceptor ligands. This is slightly closer to 180° for 5  is already preformed in complexes 3 and 4, and thus facilitates the rearrangement.After these observations, the question arises as to why complex 1–5. All spectra could be simulated  and show a coupling to 195Pt (abundance of 33.3 % and nuclear spin I=1/2) with no other resolved hyperfine splitting.To gain further insights into the electronic structure of the redox intermediates, EPR spectroelectrochemistry was applied. Electrolysis inside the EPR cavity led to the observation of signals for the one‐electron‐reduced and one‐electron‐oxidized forms of all complexes g‐value of the radical cationic compounds, with the g‐value being slightly higher for the phenylendiamide ligands than that of the catecholates or the amidophenolate ligands. The hyperfine coupling constants (hfcc) vary rather broadly from 2.73 mT for 1 to 11.90 mT for 3, indicating varying degrees of contribution from the platinum center .The nature of the donor atoms on the donor ligand has a certain influence on the g‐values of the radical anionic forms are almost the same with the only exception being complex 2, most likely owing to the tetrachloro substitution. The same applies for the hfcc, which is on average around 9 mT, except for 2. These values further substantiate that the first reduction is based on the acceptor ligand. The experimental observations are well‐reproduced by a spin population analysis, which correctly predicts the spin to be localized mostly on the pimp acceptor ligand for the reduced species and mostly centered on the quinoid donor ligand for the oxidized species .The 1–5, which we have already employed for various correlations (see above). The frontier orbitals for all of the complexes show a certain metal character but are nevertheless mostly ligand‐based and display mostly π‐character. The discussed deviation of the two nitrogen donor atoms for 3, 4, and 5 is also apparent in the orbital picture. The HOMOs for 1 and 2 exhibit a mirror plane (perpendicular to the π‐system and dissecting the OCCO chelate), whereas we observed a “distorted symmetry” for 3, 4, and 5.To further rationalize the electronic structure of the complexes, DFT calculations on the B3LYP/def2‐TZVP level were employed. The optimized structures (BP86/def2‐TZVP) are in good agreement with the crystallographic data. Figure 1–5, it is insightful to analyze the electronic flux densities for the optically active transitions from the ground state to the first absorption band. The electronic flux density yields space‐resolved information about the flow of electrons during the excitation process. Because the first absorption band at the TD‐DFT/B3‐LYP level is dominated by a HOMO–LUMO transition, the electronic flux densities are calculated in the single‐active electron approximation. All quantities were computed using ORBKITTo characterize the ligand‐to‐ligand charge transfer mechanism for complexes 1, 2, and 5, which correlates with a laminar, pincer‐type electron flow on the donor ligand as well. The planarity between the donor and acceptor ligands leads to a simple x‐shaped flow of the electrons from the coordination atoms of the donor ligand over the platinum atom to the nitrogen atoms of the acceptor ligand. Despite their similarities, a stronger, more localized electron flow is observed on complex 2. This is possibly due to the symmetry of the substituents on the phenyl ring of the donor. In contrast, the electron flow pattern at the donor ligands of complexes 3 and 4 is more intricate due to their nonplanar structure. This indicates that more electrons are available in the space between the donor ligand and the metal center, which in turns favors a through‐space mechanism for the electron transfer. The electron flow on the acceptor ligand is perturbed and reduced in intensity in both complexes but, surprisingly, the spatial extent of the electron transfer remains similar. For a more quantitative measure, the charge transfer (CT) number can be computed as the product of the donor population and the acceptor population, as in Equation As discussed above, the complexes all reveal an intense ligand‐to‐ligand charge transfer for the lowest energy transition, from the various ligand donors to the iminopyridine acceptor. On the acceptor ligand of all five complexes, the electronic flux exhibits a large degree of delocalization, with a pincer‐type electron flow incoming through the platinum center, over both nitrogen atoms and to the neighboring carbon atoms through the conjugated π‐system. The delocalized flow is particularly laminar for complexes Pi are the respective Mulliken projectors on the donor and acceptor. Despite the marked differences in the electron flow mechanisms observed above, the charge transfer numbers were found to be similar in complexes 2–4, ranging from 0.757 for complex 2 to 0.784 for complex 3. Of the three planar structures, only complex 1 was found to have a slightly smaller CT number (0.711). This correlates well with the smaller electron flow observed on the donor ligand. By looking at the three largest CT numbers (complexes 3–5), it appears that choosing a ligand which increases through‐space electron flow can increase the degree of charge transfer. This can come at the expense of a less laminar flow, as in complexes 3–4, which we rather attribute to a structural effect.where N‐phenyltetrahydroisoquinoline (ISQ) with acetone and nitromethane. Special focus was put on the role of the donor atoms, which is why complexes 1, 4, and 5 were used for a preliminary study with an [OO], [NN], and [ON] donor ligand, respectively. We optimized the reaction conditions in terms of oxygen saturation and overall irradiation time . Pure oxygen was bubbled through the solution for 2 minutes, 30 minutes, or not at all . Interestingly, we observed a high yield for complex 1 after only 2 minutes of bubbling and a long irradiation time of 15 hours in nitromethane, and a considerably lower yield for the same conditions in acetone PtX2 system for photocatalysis and other applications.Cross‐dehydrogenative coupling (CDC) has gained considerable popularity among organic chemists as an atom‐efficient method for C−C bond formation.1 in DMF (bubbled for 30 minutes) for 3 minutes with an excess of α‐phenyl‐N‐tert‐butylnitrone (PBN). The EPR spectrum shows a triplet  in the catalytic cycle, complex 1 was tested in the oxidation of 1,5‐dihydroxynaphthalene to 5‐hydroxy‐1,4‐naphthoquinone (or juglone). The observation of new bands in the visible region  that correspond to juglone are indicative of singlet oxygen being involved in the reaction.1 will most likely have a relatively low excited‐state oxidation potential, which will not suffice to oxidize ISQ.To further substantiate the involvement of dioxygen as an oxidizing agent, we irradiated a solution of complex t Figure , indicat1O2 in Scheme This leads us to the conclusion that a similar catalytic cycle as already described in various literature reports is operating here  and catalytic potential to the full, and synthesizing the nickel and palladium analogues for their potential use in catalysis and switching.We have presented a series of new platinum(II) donor–acceptor systems with the lesser used phenyliminomethylpyridine ligand and a focus on the influence of the donor ligand. The title compounds were extensively characterized by cyclic voltammetry and UV/Vis/NIR‐ and EPR spectroelectrochemistry. All complexes displayed from two up to four redox events of varying reversibility. Density functional theory reproduced the experimental absorption spectra nicely, and the dynamic electron fluxes in such systems were investigated for the first time. UV/Vis/NIR spectroelectrochemistry revealed interesting redox‐driven linkage isomerism during the oxidation of complexes The authors declare no conflict of interest.As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re‐organized for online delivery, but are not copy‐edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors.SupplementaryClick here for additional data file.


In view of the current obesity epidemic, studies focusing on the interplay of playing outside (PO), screen time (ST) and anthropometric measures in preschool age are necessary to guide evidence-based public health planning. We therefore investigated the relationship between average time spent PO and ST from the ages 3 to 6 years and anthropometric measures at 6 years of age.PO and ST of 526 children of the European Childhood Obesity Project (CHOP) were annually assessed by questionnaire from 3 until 6 years of age. Body weight, waist circumference and height were measured at 3 and 6 years of age to calculate Body-Mass-Index z-Scores (zBMI) and waist-to-height ratio (WTH). Linear, logistic and quantile regressions were used to test whether average time spent PO and ST in the 4 year period had an effect on anthropometric measures at age 6 years.Longer daily ST was associated with a higher zBMI (P = 0.002) and WTH (P = 0.001) at 6 years of age. No significant associations were found for time spent PO. Each additional hour of average ST during the 4 year period resulted in a 66% higher risk of having a zBMI score over 1 (P < 0.001) and almost twice the risk (94% higher risk) of having an zBMI score over 2 (P < 0.001) at 6 years.Excessive ST during preschool age is a risk factor for increased zBMI at 6 years, regardless of time spent PO. Reducing high levels of ST during preschool age, for e.g. at least 1h per week, could help preventing childhood obesity. Over the last decades childhood obesity turned out to be one of the major public health concerns, as long-term consequences on health become more obvious . ChangesChildren’s lifestyle and how they spent their free time have changed in the last decades, with a steady decline of physical activities like outdoor play in 3- to 12-year-olds . HoweverWhile the amount of time spent PO decreases, media use in children and adolescence becomes more and more common , and staAlthough pathways might be clear, there is a distinctive lack of prospective studies in preschool children examining the relationship between PO, ST and anthropometric measures at later ages. In order to make this gap smaller we aim to test whether time spent PO or ST from 3 to 6 years of age is associated with anthropometric measures at 6 years of age.clinicaltrials.gov/ct2/show/NCT00338689. Details and the primary outcome are published elsewhere [The study population used is a subset of the “European Childhood Obesity Project” trial, which was designed as a double-blind randomized control trial registered at clinicaltrials.gov as NCT00338689; URL: lsewhere , 18. In The study was conducted according to the principles expressed in the Declaration of Helsinki. The local ethics committees of each study center approved all study procedures: Belgium , Germany , Italy , Poland , and Spain . Written informed parental consent was obtained for each infant.2, which has been proven to be a good measure for child overweight and obesity [Children’s weight, height and waist circumference were measured at study centers at the 3 and 6 years follow-up visit. Standard operating procedures based on the World Health Organization’s Multicenter Growth Reference Study were applied . The sam obesity . Age- an obesity . Waist t obesity .At the 3 year, 4 year, 5 year and 6 year follow-up questionnaires were handed out, including four questions asking for a typical weekday or weekend day in the last month. A four items questionnaire was used to assess time PO and ST, which was filled by parents before or during study visits. To asses children’s time PO their parents were asked to recall: “How much time would you say your child spends playing outdoors on a typical weekday?” and “How much time would you say your child spends playing outdoors on a typical weekend day?”. For ST similar questions were used: “How much time would you say your child spends watching TV, playing videogames or using the computer on a typical weekday?”“How much time would you say your child spends watching TV, playing video games or using the computer on a typical weekend day?“.Answers should be entered in free text field in hours and minutes. Identical questionnaires are used in other studies and validated in similar populations . The meaAdditional to gender and study country seven covariates were considered in the analysis of which following covariates were collected at study recruitment: highest education level of mother and father according to International Standard Classification of Education 1997 levels, defined as low (level 0–2), middle (level 3–4) and high (level 5–6) , pre-preData are reported as mean (μ) ± standard deviation (SD) for continuous variables and as number (n) and percentage (%) for factors. Main predictor variables were time spent PO and ST. Implausible values of more than 10 hours of ST per day were excluded (4 data points). Both PO and ST showed to be relatively stable behaviors over the preschool period: Spearman correlation coefficients of successive PO measurements ranged from 0.51 to 0.60; correlation coefficients of successive ST measurements coefficients ranged from 0.60 to 0.64. We combined consecutive measurements of PO and ST into one average PO and one average ST variable, to estimate the average time spent PO and ST over the whole preschool period. Variables PO and ST used in the data analysis were calculated as individual means of children’s PO and ST measurements over the 4 years period. As follow-up of all participants at all time points was not achieved, we defined that only children with at least two measurement points with both PO and ST data at the respective time point were included in the analysis. We defined overweight as a zBMI at 6 years >1, obesity as a zBMI at 6 years >2 and WTH at 6 years > 0.5 as a measure of increased central adipose tissue associated with worsened cardiometabolic risk , 26.2. Children with more measurements points were assumed to have a more precise measure compared to children with less measurement points. Therefore, regression models were weighted according to the number of measurement points of PO and ST (two to four measurement points) available per child. Average PO and ST variables were potentially age biased, as some children only had data from later time points, which had an average higher ST and lower PO.In the primary analysis we looked at effects of average time spent PO and average ST on anthropometric outcomes: Two separate linear regression models were built with zBMI and WTH at 6 years as outcomes and average ST and average time spent PO as main predictors. A third mutually adjusted linear regression model with both PO and ST as predictors was used. All models were adjusted for zBMI or WTH at age 3 years, respectively, intervention group and country. Sex was only added to the WTH model, as zBMI already incorporated sex. Additional covariates (see covariate section) were selected based on highest adjusted Rth to 90th percentiles were built in steps of ten. Beta estimates for each quantile were plotted to visualize differences in effect sizes over the zBMI/WTH distribution of the sample.Secondly, we applied logistic regression to assess the impact of PO and ST on overweight, obesity and increased WTH. Adjustment was identical to linear regression models. Furthermore, to explore whether effect estimates differ by quantiles of zBMI and WTH, quantile regression models for the 10Additional bias could arise from cross-sectional associations between PO/ST and anthropometrics at the last time point. Therefore sensitivity analysis was conducted with two separate models, one with children, who completed PO and ST measurements with 3 years and 4 years of age. Another model was built with children, who completed PO and ST measurements with 3 years and 4 years and 5 years of age.Another sensitivity analysis was conducted by employing multiple imputation to avoid bias from missing data. All missing values of outcome and exposure variables from children, who participated at either baseline or follow-up were imputed by a bootstrapping-based algorithm for time series data, resulting in five imputed data sets –29. EstiEight hundred children participated at either baseline or follow-up visit with valid anthropometric data. Of those 800 children at least one PO or ST measurement was available for 734 children, where 731 completed the PO questionnaire and 729 the ST questionnaire at least once. In total 526 children were included in the analysis with zBMI data at 3 and 6 years and at least two measurements of PO and ST points with PO and ST data available; 495 for WTH . Of thesth to 90th percentile of zBMI and WTH. Effect estimates for PO were similar across all percentiles of the zBMI and WTH distribution. Looking at ST, higher effect estimates were observed for the upper percentiles of zBMI . For WTH effects start to increase from the 70th percentile upwards .Sensitivity analysis using only the average PO and ST of the first three  and two Our analyses showed that average ST between 3 and 6 years was associated with a higher zBMI and WTH at 6 years, independently of average time spent PO in the same time frame. An hour of additional ST per day resulted in an almost twofold risk of being obese at 6 years of age. Effect of ST differed by zBMI and WHT percentile, where the upper percentiles representing overweight and obese children showed a greater increase of zBMI and WTH than normal weight children. These results emphasize the need for early intervention to focus on reduction of sedentary activities like ST, especially in already overweight children.Literature support the results of our study of a positive association between ST and body size, independent of time spent PO. A cross-sectional analysis of 759 preschool children from the GECKO Drenthe cohort found that long ST is related to a higher BMI . In the Our study and concurrent literature confirm that negative effects of ST are already consistent in young children. Kuhl et al. describe ST as a major behavioral correlate of obesity in preschoolers and emphasize the need for intervention . Two othth percentile of zBMI.One possible explanation for the negative effects of ST is its relationship to negative dietary habits. Two recent studies found that increased ST is associated with higher energy intake, less consumption of vegetables and fruits and a higher consumption of sugar-sweetened beverages –44. A reA definite strength of our study is the longitudinal and multicenter design. This makes it possible to give a statement about the direction of effects in a rather large population group. Especially compared to cross-sectional studies, which often rely on rather locally restricted samples. The results of our study are based on a European birth cohort, which makes results generalizable for children from these five European countries. However, the population might not be fully representative as children were mainly from urban areas and about two thirds of them took part in the intervention during the first year of life . AdditioResults of this study have shown that ST is associated with an increase in zBMI and WTH over the course of 4 years. Each additional hour of ST doubled the risk of becoming overweight or obese at the age of 6 years, independent of baseline weight status and time spent PO. Effects of ST were more pronounced in higher percentiles of zBMI and WTH. PO had little effect on the early anthropometric development of children. Reducing media use in preschool and encouraging children to a more active lifestyle, could help fighting childhood obesity.S1 Table(DOCX)Click here for additional data file.S2 Table(DOCX)Click here for additional data file.S3 Table(DOCX)Click here for additional data file.S4 Table(DOCX)Click here for additional data file.S5 Table(DOCX)Click here for additional data file.S6 Table(DOCX)Click here for additional data file.S7 Table(DOCX)Click here for additional data file.S8 Table(DOCX)Click here for additional data file.


Background: Stroke is one of the most common neurologic injuries worldwide. Over decades, evidence-based neurorehabilitation research and advancements in wireless, wearable sensor design have supported the deployment of technologies to facilitate recovery after stroke. Surface electromyography (sEMG) is one such technology, however, clinical application remains limited. To understand this translational practice gap and improve clinical uptake, it is essential to include stakeholder voices in an analysis of neurorehabilitation practice, the acceptability of current sEMG technologies, and facilitators and barriers to sEMG use in the clinic and the community. The purpose of this study was to foreground the perspectives of stroke survivors to gain a better understanding of their experiences in neurorehabilitation, the technologies they have used during their recovery, and their opinions of lab-designed and commercially-available sEMG systems.Methods: A qualitative, phenomenological study was completed. In-depth, semi-structured interviews were conducted with eight stroke survivors  and two caregivers from a large metropolitan region. A demonstration of four sEMG systems was provided to gather perceptions of sensor design, features and function, and user interface. Interviews were audio-recorded, transcribed verbatim, and coded for analysis using constant comparison until data saturation was reached.Results: Three themes emerged from the data: (Surface EMG has potential….but…” highlights the recognition of sEMG as a valuable tool but reveals a lack of understanding and need for clear meaning from the data; (Tracking incremental progress over days or years is important” highlights the persistence of hope and potential benefit of sEMG in detecting small changes that may inform neurorehabilitation practice and policy; and (Neurorehabilitation technology is cumbersome” highlights the tension between optimizing therapy time and trying new technologies, managing cost, logistics and set-up, and desired technology features.he data:  “Surfacehe data;  “Trackinicy; and  “NeuroreConclusion: Further translation of sEMG technology for neurorehabilitation holds promise for stroke survivors, but sEMG system design and user interface needs refinement. The process of using sEMG technology and products must be simple and provide meaningful insight to recovery. Including stroke survivors directly in translational efforts is essential to improve uptake in clinical environments. Over the past decades, there has been a prolific amount of research and development of technology to enhance both the understanding of neurologic injuries and the application of evidence-based neurorehabilitation interventions. Surface electromyography (sEMG) is one such technology that has undergone rapid advancement in development, but has yet to reach its full translational potential to help drive neurorehabilitation and maximize recovery. Understanding this translational gap must consider multiple factors across a complex landscape of healthcare provision, especially given the public/private healthcare model in the United States. Successful deployment of sEMG in clinical environments relies on an interaction of system design, funding, translational research findings, clinician training, and user acceptance, among many other factors. While user acceptance of neurorehabilitation technology is just a small piece of a much larger puzzle, it is an essential one, and a more explicit understanding of the perceptions and experiences of individuals with neurologic injury, such as stroke, is warranted to better understand the barriers, facilitators, and untapped potential of sEMG technology in clinical neurorehabilitation,Stroke is one of the most common neurologic injuries worldwide , 2. ReceSurface EMG today is used in research and clinical environments across a wide variety of physiological and engineering applications relating to rehabilitation, sport performance, occupational performance, and beyond . More spOne potential reason for the slow clinical uptake of sEMG and related neurorehabilitation technologies may be the paucity of perspectives in research from clinicians as providers of sEMG assessment or intervention, and individuals with neurologic conditions and their caregivers as recipients of sEMG assessment or intervention. Considering sEMG alongside other neurorehabilitation technologies more broadly, the literature is lacking a clear picture of how and how often these technologies are used in clinics across the US, and how technology users and their caregivers respond to the design, logistics of use, and output of the devices. However, user and caregiver perspectives are a key untapped resource in the design and implementation of rehabilitation technologies such as sEMG, and have the potential to richly contextualize the barriers and facilitators that affect technology acceptance and use. For example, within the broader realm of neurorehabilitation technology, Alt Murphy et al.  recentlyAdditional qualitative work with stroke survivors and clinicians has also explored perspectives and experiences of the rehabilitation process itself, as well as technologies such as virtual reality, gaming, robotic exoskeletons, or other wearable devices, but little work has focused specifically on sEMG –29. One The literature notes that the introduction of novel healthcare technologies into existing clinical practices can be challenging, as the process often disrupts engrained care routines . ResistaThe purpose of this early-stage study was to foreground the perspectives of stroke survivors and gain a better understanding of their experiences in neurorehabilitation, the technologies they have used during their recovery, and their introductory perceptions of one lab-designed prototype and three commercially available sEMG systems. Centering these perspectives is critical to understanding the barriers and untapped potential of sEMG and other neurorehabilitation technologies that may support the recovery of individuals with neurologic injuries. This qualitative work complements and builds upon past milestones in sEMG research across rehabilitation and engineering fields. It offers a preliminary look at baseline user perspectives to inform more robust research in the future, and provides a unique opportunity to leverage user-centered perspectives to support potential innovations in sEMG design, implementation, and outcomes.All procedures in this study were approved by the authors' institutional review board, and written consent was obtained by all participants prior to initiation of study procedures. Participant names are pseudonyms to protect privacy and confidentiality. This qualitative study was conducted using a phenomenological approach, which is ideal for understanding the lived experiences of a group of participants with similar characteristics . UltimatThis study was conducted by a multidisciplinary research team, including a physical therapist with qualitative research expertise, mechanical engineer with wearable sensor expertise, and two research scientists. All members of the team had extensive training and experience in the clinical application of sEMG systems to track muscle activity changes in stroke survivors. In addition to this qualitative work, the research team was concurrently collecting sEMG data from stroke survivors in acute care and community-based settings. Therefore, the researchers were well-positioned to engage with and provide baseline information to the participants about sEMG technology.Semi-structured interviews were conducted to obtain primary source thoughts, opinions, and interpretations from the participants, using an interview guide that was developed by the authors, edited for content until consensus was reached, and piloted with a volunteer to ensure clarity of question content and order. During each interview, a brief demonstration of four, research lab-owned sEMG systems was conducted. This included one lab-designed sEMG sensor prototype as well as three commercially available sEMG systems, chosen to represent a broad range of system design, aesthetic, and capabilities: (A) MC10 BiostampRC® ; (B) Thalamic Labs Myo™ Armband ; (C) Delsys Trigno™ ; and (D) Epidermal Sensor System , a lab-designed prototype with sensor filament embedded in medical tape. See Interviews were conducted at a location of the participant's choosing, with half the interviews taking place at the participant's home, and half taking place in university settings such as an office or research lab. All interviews were audio-recorded, transcribed verbatim, and de-identified.n = 8) had post-secondary vocational training or college degrees, with employment backgrounds including business and finance administration, teaching, musician, and aerospace engineering. One participant had previously worked in a research and development capacity with activity monitoring technology for nearly 20 years, and another had participated in a prior research study using sEMG for serious gaming. The remaining participants did not have prior experience with sEMG, though many had used or trialed related neuromuscular rehabilitation technologies such as electrical stimulation or biofeedback, as well as ubiquitous lay technologies such as commercial fitness or activity trackers, following their stroke.Participants were recruited via convenience sampling through stroke clinics and rehabilitation professional contacts across a large metropolitan area. To be included in the study, participants must have been over the age of 18 years, have the cognitive capability to consent for themselves, have had any type of stroke in the past or be the spouse or caregiver of the stroke survivor, and demonstrate proficiency communicating in English. Potential participants were excluded from the study if they were under the age of 18 years, not able to cognitively consent for themselves, or communicate proficiently in English. Stroke survivors with aphasia or limited communication capabilities were included in the study along with their spouses/caregivers. Ten participants across the Seattle metropolitan region completed the study, including eight stroke survivors and two spouses/caregivers. Of the stroke survivors, four were male and four were female, ranging in age from 49 to 78 years old (mean = 65 years), and ranging from 6 months to 12 years post-stroke (mean = 4.75 years). One male and one female spouse/caregiver participated in the interviews with their respective partners. Two participants had mild to moderate expressive aphasia, one participated in the interviews independently, and another participated to the greatest extent possible with the assistance of his spouse. Most participants  participants felt that sEMG could be a useful way to deliver more objective data to support their self-perceived assessment of functional recovery  also highlighted the potential importance of sEMG in providing objective information to their clinical teams, noting that it could fill a gap for medical providers in challenging or ambiguous situations, and assist in making accurate prognostic decisions, providing concrete feedback to survivors and caregivers, or improve rehabilitation productivity , there was recognition of sEMG as a means to invite a multidisciplinary, user-centered technology experience into rehabilitation and recovery. Participants were excited about the prospect of brainstorming sessions to leverage existing technologies and innovate with new ideas, and highlighted the importance of the technology user as a primary stakeholder with lived expertise in regard to these healthcare advances  noted they would appreciate the precision offered by sEMG and the potential to identify small changes during rehabilitation  also noted that data describing these incremental changes noted during recovery could be essential for improving policy and access to neurorehabilitation services as well as technology such as sEMG. However, it was clear to participants that if sEMG will become a justifiable and viable rehabilitation technology, that it must demonstrate its significance to both users and insurance companies  enhance recovery. For example, even for a participant whose previous job was to create and test activity monitors, cost and accuracy were issues , Quote 1n = 7) expressed a preference for lower tech adaptive devices, or more ubiquitously available lay technology. Over half (n = 6) of the participants had tried wrist-worn commercial fitness trackers but reported mixed results. Those that responded favorably noted the device's potential for motivation, and those with less favorable opinions cited a lack of accuracy or customizability (n = 5) the participants (n = 5), even when self-cueing was performed by taking photographs or drawing on the skin. Participants noted the need for refresher training with their therapists when using this technology (All participants had purchased some type of rehabilitation technology out of pocket, and described similar sentiments about cost, maintenance, and reuse of supplies (Trends emerged, however no consensus from the participants was reached when discussing the benefits and drawbacks perceived from the demonstration of four sEMG systems. In general, participants felt the Delsys Trigno™ was a better research tool and impractical for clinical or home use, which reflects what it and other research-grade systems were designed for. Participants appreciated the flexibility and low profile of the ESS tape sensors and the Biostamp®, but preferred the Myo™ in terms of simplicity and ease of placement without the use of stickers. Half the participants raised the issue of difficulty removing sticker backing and applying sensors one-handed (Participants also had some lofty goals for the future of creative sEMG system design and multifunctional capacity. Design ideas included built-in lighting, navigation systems, and greater connectivity between body and technology, envisioned as a social media-style account for muscle tracking (Despite a significant body of research that describes the benefits that sEMG technology may provide in better understanding stroke recovery and enhancing neurorehabilitation outcomes, as well as standards for systematically implementing sEMG, translation to clinical and community settings has been limited , 41, 42.First, our participants noted that little or no muscle monitoring technology was used during the acute and subacute phases of their recovery, these experiences underscore previous work documenting slow uptake of sEMG technologies outside research environments , 16. HowSecond, at home and in the community, stroke survivors demonstrated creativity, and resilience in adapting to their changing abilities, using a combination of high and low technology to improve participation and access. This is consistent with previous literature that describes the processes by which physical resilience is demonstrated following stroke, in part by participating in the hard work of rehabilitation, as well as capitalizing on technologies that may provide access or motivation during recovery , 47. HowThird, the participants most strongly highlighted the need for technology to provide both significant and meaningful results. Current sEMG technology had potential in their eyes, and many participants were willing to try, but the financial investment and learning curve were possible barriers, especially if it did not result in impactful information or change from their own point of view. From a perspective of stroke survivor as consumer, this issue is likely one of the most important considerations for future sEMG system design and function. Interestingly, a lack of meaningful outcomes is a frequently cited reason for rehabilitation technology abandonment, however, user-centered, participatory design and implementation strategies are still not widely used in the development of such technologies, especially with older adults –51. It iFinally, the results of this study point critically to issues of knowledge and understanding of current rehabilitation evidence. Participants discussed the need for further information and education- both for themselves and their families, but also for their healthcare providers- in regard to the benefits and potential outcomes that may be enhanced by sEMG technology. Lack of knowledge or training, time, and self-confidence, as well as a need for meaningful therapeutic outcomes surrounding use of sEMG systems are indeed themes that have been reported previously from the perspective of clinician stakeholders, who often become technology gatekeepers during stroke rehabilitation , 35. ThiIn addition to technology recommendations from members of their rehabilitation team, a majority of participants largely sought out solutions on their own or at the suggestion of other stroke survivors in their peer groups, which are viewed as an important aspect of recovery . Improvibefore technology development and deployment will strengthen resulting outcomes, as it is less helpful to constructively critique sEMG systems once they are already commercially deployed.Although the stories shared by stroke survivors and their families who participated in this research provide a much-needed perspective on sEMG technology, there are several limitations to this study. First, the participants represent a small, convenience sample contained within a single metropolitan area, and may not represent the diverse perspectives of a larger or randomized group of stroke survivors. While there was a wide range of ages, genders, stroke types, and rehabilitation courses represented among our participants, all but one individual was Caucasian. Additionally, while a standard set of factual information was shared about four sEMG systems, this is not representative of all available sEMG technologies, so participant perspectives presented here are limited to these systems only. Further, given interview time constraints and to avoid fatiguing the participants, the interviewer did not fully connect or operate the systems in real-time. Participants had the opportunity to physically interact with the sensors, observe signal printouts, and verbally or visually attend to a feature comparison chart. Further work in this area should aim to mitigate these limitations, by intentionally recruiting racially diverse participants, conducting interviews across a wider geographic area, and involving the users in real-time set up and implementation of the sEMG systems over a longer study period to obtain perspectives after full immersion in the processes. Future research should also combine user and clinician perspectives together during rehabilitation care and further assess clinician training in neurorehabilitation technology to determine how closely perspectives align and how therapeutic relationships may affect responses to sEMG technology. Finally, while these perspectives are useful, further user, clinician, and engineering collaboration Perspectives of individuals with neurologic injuries and their caregivers are one central piece of a broader discussion of factors influencing improved translation of sEMG technology use into clinical settings. The stroke survivors in this study felt that sEMG would be a useful tool for motivation and acquisition of objective data, but that the user interface would have to be simple, available in multiple formats based on the preferences of the user, and provide meaningful feedback for participation in real-world activities, not just exercises. Participants highlighted essential features of sEMG systems, including low cost, flexibility, intuitive and independent use and interpretation, disposability, and comfort. Further translation of sEMG technology for neurorehabilitation into clinical and community environments holds promise, but sEMG system design and user interface needs refinement, and training and education opportunities for clinicians to leverage sEMG technology throughout all phases of rehabilitation following stroke is warranted. Including stroke survivors directly in translational efforts, particularly in creating sEMG system outputs and feedback that is meaningful and motivating to users, is essential to improve uptake in both clinical and community environments.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by The University of Washington Human Subjects Division. The patients/participants provided their written informed consent to participate in this study.All authors contributed meaningfully to the preparation of this manuscript. HF conducted all the interviews. HF and CP completed primary data analysis. KS and KP completed secondary data analysis. All authors contributed to the writing and editing of the manuscript and equipment used in the study is owned by the Steele Lab in the Department of Mechanical Engineering at the University of Washington. Photos of sEMG systems were taken by HF and are provided courtesy of the Steele Lab. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


To characterise the physiological profiles of trained handcyclists, during recumbent handcycling, to describe the physiological responses during a 16 km time trial (TT) and to identify the determinants of this TT performance.Peak), peak rate of oxygen uptake (2Peak), aerobic lactate threshold (AeLT) and PO at 4 mmol L−1 (PO4), were determined. Participants also completed a 16 km simulated TT using the same experimental set-up. Determinants of TT performance were identified using stepwise multiple linear regression analysis.Eleven male handcyclists performed a sub-maximal and maximal incremental exercise test in their recumbent handbike, attached to a Cyclus II ergometer. A physiological profile, including peak aerobic power output , AeLT = 87 ± 13 W and PO4 = 154 ± 14 W were recorded. The TT was completed in 29:21 ± 0:59 min:s at an intensity equivalent to 69 ± 4% POPeak and 87 ± 5% 2Peak. POPeak , PO4  and AeLT  were significantly correlated with TT performance. PO4 and POPeak were identified as the best predictors of TT performance .Mean values of POPeak, PO4 and AeLT are important physiological TT performance determinants in trained handcyclists, differentiating between superior and inferior performance, whereas 2peak was not. The TT took place at an intensity corresponding to 69% POPeak and 87% 2peak.PO Moreover, peak power output achieved during incremental tests to exhaustion (POPeak) has been related to performance  and 2Peak  have been reported in the literature . The University’s local ethics committee approved the study. Before participation, all participants provided their written, informed consent.Eleven male recumbent handcyclists , 3 spinal cord lesions incomplete (8th–9th thoracic vertebra), 3 lower limb amputees and 1 diplegic cerebral palsy) volunteered to participate. All participants had competed in handcycling or paratriathlon, at a national or international level , and maximal incremental exercise test, to assess POPeak, 2Peak, and peak heart rate (HRPeak). Ventilatory thresholds were not determined as there has been mixed results to their suitability in this sample . Breath-by-breath gas analysis —for calculation of 2, carbon dioxide production and respiratory exchange ratio (RER)—HR  and rating of perceived exertion , by using linear interpolation methods as used in the handcycling literature , calculated as the ratio of external work to energy expended . Energy expenditure was calculated from the product of 2 and RER and the standard conversion table  and maximal test  to TT performance . Variables that were significantly correlated with 16 km TT performance were inputted into a stepwise multiple linear regression to establish the most important determinants of 16 km TT performance. Durbin–Watson test was used to indicate the independence of variables entered into the regression. Tolerance and variance inflation factors were also used to assess multicollinearity within the data.Pearson’s product-moment correlation was used to analyse the relationship between variables from the sub-maximal   before plateauing during the remainder of the TT  before plateauing between the 3rd km and 14th km and significantly increasing in the final 2 km (P < 0.001) ], while ME% was found to significantly decrease . The average intensity of the TT’s was equivalent to 69 ± 4% of POPeak and 87 ± 5% of 2Peak  Fig. b. \documentclass1pt{minimaentclass1pt{minimaPeak , PO4 , AeLT  and TT performance (Table 4 was the strongest predictor accounting for 59.3% of the variance in 16 km TT performance (P = 0.006). The addition of POPeak  to PO4 provided a stronger prediction model, accounting for 78.3% of the variance in performance (P = 0.002). A Durbin–Watson value of 1.501 indicated that variables within this model were sufficiently independent and not autocorrelated. Tolerance values of 0.741 and a variance inflation factor of 1.350 further indicate that multicollinearity was not an issue for this regression model.The highest correlations were observed between POPeak, PO4 and AeLT. Conversely, 2Peak, both absolute and relative, were not correlated with TT performance.The current study investigated the physiological responses during a 16-km TT, in a population of national and international recumbent handcyclists. Extending the recent work of Stangier et al. , this st2Peak and POPeak values than previously reported  to the participants from previous studies  and POPeak (281 W) values averaged 5 handcycling sessions a week totalling 8 h week−1 with a self-reported distance of 170 km week−1. Therefore, the higher physiological values observed in the current study are likely to be due to advances in endurance training regimes  to a 20 and 22 km TT, reported by Graham-Paulson et al. (−1). During the TT participants maintained a constant PO, similar to Fischer et al. (Peak or ~ 25% greater than PO4 (using methods similar to the current study). This high exercise intensity indicates the contribution of the anaerobic pathways to supply energy during a typical handcycling TT. Therefore, a high anaerobic capacity may play an important role in handcycling TT success, like able-bodied cycling , which supports previous research  and PO4 . Contrary to the previous handcycling literature  and relative 2Peak (r = − 0.21) were not correlated with TT performance. Therefore, these results suggest that, in highly trained handcyclists with a heterogenous injury description, POPeak and blood lactate (AeLT and PO4) are better predictors of TT performance than 2Peak. In able-bodied athletes, fractional utilisation of 2Peak, i.e. intensity at lactate threshold, has long been understood to better predict endurance performance in highly trained athletes whilst POpeak has consistently been shown to predict cycling performance, regardless of task duration or test profile  are better indicators of TT performance than 2Peak. From this data, it may be recommended that testing for POPeak or PO4 is conducted with handcyclists to infer performance potential. Although assessing the latter requires specialist equipment for BLa measurement, PO4 is also commonly used for training intensity prescription.The current study extends previous work, which was limited to handcyclists with a spinal cord injury  and H4 (n = 6) would allow a comparison between classes. Finally, the inter-individual variability of physiological parameters in the study’s cohort is acknowledged. Heterogeneity is inherent in Paralympic populations due to athletes’ spectra of impairments. Furthermore, variation in physiological parameters are likely largely mediated by training history and performance standard.An electronically braked ergometer was used to simulate the TT. The electronic braking meant that handcyclists had to pedal continually to apply power, which differs from a road TT. The corners and gradients throughout a road TT course would allow the handcyclists to recover for short periods (0–5 s). Furthermore, as the ergometer was fixed to the floor, the influence of aerodynamic drag, steering and braking were removed. Future research should aim to collect TT data on the road, in a competition if possible, and compare with laboratory-based findings. Additionally, recruiting participants from the H1, H2 and H5 classes, along with a greater number within H3 . A protocol equivalent to 70% POPeak is recommended, in future studies, to replicate 16 km TT intensity.The current study revealed that the best predictors of 16 km TT performance, in a population of trained recumbent handcyclists, were PO


Using blood specimens from untreated early Parkinson's disease (PD) patients from the DATATOP trial, we found that subjects in the low serum vitamin B12 tertile experienced greater annualized change in ambulatory capacity score, whereas those with moderately elevated (>15 μmol/L) total homocysteine had greater annualized declines in the Mini‐Mental State Exam.In this this study we sought to determine whether levels of cerebrospinal fluid (CSF) B12 markers were also associated with progression of PD.The annualized change in the UPDRS “walking” item, a component of the ambulatory capacity score, was worse in the low B12 tertile. No association with change in the Mini‐Mental State Exam was seen for those 7% with the highest baseline CSF total homocysteine.Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.In these untreated early‐PD subjects, low CSF B12 predicted greater worsening of the UPDRS “walking” item, whereas CSF total homocysteine was not associated with progression of cognitive impairment. These findings extend and partially support our findings in serum. © 2020 The Authors.  In our recent investigation of vitamin B12 status in untreated early Parkinson's disease (PD), using 680 baseline blood samples from the Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism (DATATOP) cohort,Although it is possible that the association of low B12 with more rapid impairment of ambulatory capacity is mediated by its known role supporting central and peripheral nervous system myelination, recent studies have shown that B12 inhibits α‐synuclein fibrillogenesisBecause cerebrospinal fluid (CSF) is often considered the preferred biofluid to assess central nervous system status,DATATOP was a double‐blind, randomized trial that tested whether treatment with deprenyl (selegiline hydrochloride) and/or the antioxidant alpha‐tocopherol slowed PD progression. The study enrolled 800 participants between 1987 and 1988.CSF was collected at the baseline visit after overnight bed rest. At the time of collection, the CSF was rapidly frozen for storage at −70°C. We used samples obtained from the middle or end of the CSF collection, which were not stored with metabisulfite preservative.CSF B12 was measured using a microbiological assay.tHcy was determined by LC‐MS/MS using a modification of a previously described method.P < 0.004 was considered statistically significant.The annualized change in PD‐related motor scores and MMSE were determined based on the change from baseline to the primary end point or the final visit if the primary end point was not reached as previously described.Of 581 baseline CSF samples available, we measured B12 in 571 specimens, holoTC in 565 samples, MMA in 576, and tHcy in 572. The reason for the inability to measure analytes in samples from all participants was because of insufficient CSF volume. The geometric mean ± SD for CSF B12 was 17.3 ± 7.2 pmol/L, for CSF holoTC was 15.5 ± 9.4 pmol/L, for MMA was 0.34 ± 3.9 μmol/L, and for tHcy was 58.7 ± 43.7 nmol/L of 0.57, P < 0.0001; however, the mean CSF B12 level was considerably lower, about 6% of the corresponding mean serum measurement (geometric mean of CSF B12/geometric mean of serum B12). CSF holoTC had an an r of 0.67 with serum holoTC, P < 0.0001, and mean CSF holoTC was 22% of mean serum levels. CSF MMA correlated with serum MMA with an r of 0.69, P < 0.0001, and mean CSF MMA was 170% of mean serum measurement. Finally, CSF tHcy had an r of 0.74 with serum tHcy, P < 0.0001; mean CSF tHcy was 0.6% of the mean serum measurement.CSF analytes showed significant associations with serum analytes, although the CSF levels were substantially lower than the serum levels for all except MMA. For example, CSF B12 compared with serum B12 measurements showed a correlation coefficient .Table P < 0.02; eTable P < 0.01; eTable Given the strong correlation between holoTC and B12  predicted an annualized decline of 1.65 points in the MMSE compared with a 0.14‐point increase in those with tHcy ≤15 μmol/L, no association was observed in those subjects with the highest 7% of CSF tHcy Dr. Christine reports research grants from Voyager Therapeutics, Inc, NINDS, and from Michael J. Fox Foundation.Dr Auinger reports none.Nasrin Saleh, Miao Tian, Teodoro Bottiglieri, Erland Arning, Nam K. Tran, and Per Magne Ueland: none.Ralph Green reports a donation from an anonymous private foundation.Table 2A Adjusted Mean Annualized Change in Outcomes According to Tertiles of Baseline Serum Holo TC LevelsTable 2B Adjusted Mean Annualized Change in Outcomes According to Tertiles of Baseline CSF Holo TC Levels.Click here for additional data file.Table 3A Adjusted Mean Annualized Change in Outcomes According to Baseline Serum Total Homocysteine LevelsTable 3B Adjusted Mean Annualized Change in Outcomes According to Baseline CSF Total Homocysteine LevelsClick here for additional data file.Figure S2 Supporting informationClick here for additional data file.


CSF findings help to distinguish TBE from other viral infections. In cases with CSF pleocytosis and a positive history for a stay in or near an endemic area, TBE antibodies in CSF and serum should be determined, especially if granulocytes in CSF cell differentiation and/or an intrathecal IgM synthesis is present.To investigate whether and how cerebrospinal fluid (CSF) findings can contribute to distinguish tick-borne encephalitis (TBE) from herpes simplex virus (HSV) and varicella zoster virus (VZV) induced central nervous system (CNS) infections . Chart review and identification of TBE, HSV- I, and VZV-I was carried out, fulfilling the following criteria: (1) clinical signs of encephalitis and/or meningitis, (2) complete CSF analysis and confirmed viral etiology by either PCR or antibody testing in CSF, (3) hospitalized patients, and (4) available brain magnetic resonance imaging (MRI). Fifty-nine patients with 118 CSF/serum pairs were included. These comprised 21 with TBE (35 CSF/serum pairs), 20 (40 CSF/serum pairs) with HSV-I, and 18 (43 CSF/serum pairs) with VZV-I. In contrast to HSV-I and VZV-I, CSF cell differentiation in TBE showed more often an increased (>20%) proportion of granulocytes ( Tick-borne encephalitis (TBE) is an acute inflammatory disease of the central nervous system (CNS) caused by an RNA flavivirus of the same name  and transmitted by ticks . In EuroThe standard method to diagnose TBEV infections is the detection of specific IgM and IgG antibodies in serum and/or CSF if there is a positive history for a stay in an endemic area . There iTherefore, we aimed to describe cerebrospinal fluid (CSF) and clinical findings, including magnetic resonance imaging (MRI) data, in TBE in comparison with HSV- and VZV-induced CNS infections , which are the main differential diagnoses.CSF findings of patients with suspected viral CNS infections who were admitted to the Department of Neurology of the University of Ulm between July 2009 and July 2018 were reviewed retrospectively. Identification of TBE as well as HSV-I and VZV-I was carried out, fulfilling the following criteria: (1) clinical signs of encephalitis and/or meningitis; (2) complete CSF analysis including cell count and cell differentiation, CSF/serum albumin ratio, oligoclonal IgG bands (OCB), lactate, determination of intrathecal IgG, IgA, and IgM synthesis, and confirmed viral etiology by PCR or antibody testing in CSF; (3) hospitalized patients with sufficient documented clinical history; and (4) available brain MRI at the time of lumbar puncture (LP).Encephalitis was defined according to the criteria of the International Encephalitis Consortium ; encephaThe local ethics committee of the University of Ulm approved this study .p-values of less than 0.05. In this explorative analysis, there was no correction of p-values for multiple testing. Graphic Program by Albaum IT-Solutions was used to visualize the Reiber diagrams.All statistical analyses were performed using the software IBM SPSS Statistics Version 25. Continuous variables were described by median (first quartile–third quartile) and categorical variables by absolute and relative frequencies. Comparisons between the three groups were performed using Fisher’s exact test for categorical variables and the Kruskal–Wallis test for continuous variables. Post hoc analyses were performed using Fisher’s exact test and Mann–Whitney U test, respectively. Furthermore, we used multiple logistic regression analysis when confounding or effect modification was suspected, yielding odds ratios (ORs) and 95% confidence intervals (CIs). Interaction terms between two variables were calculated by multiplication. We used stepwise variable selection (forward selection based on likelihood ratio) for the identification of relevant independent variables in the regression model. Statistical significance was assumed for Anonymized data on individual patient level will be shared by request from any qualified investigator.In total, 59 patients with 118 CSF/serum pairs were included. All patients were hospitalized. MRI scans, LP, and complete CSF analysis were available. Viral etiology was confirmed by PCR in CSF or detection of increased pathogen-specific CSF/serum antibody indices (AIs) .Twenty-one patients with TBE (35 CSF/serum pairs including follow-up LP), 20 with HSV-I, and 18 patients with VZV-I  were identified. For demographic and clinical characteristics, see p < 0.01). When compared with HSV-I, TBE was significantly more often associated with a meningitic than an encephalitic presentation (p < 0.01). Inflammatory MRI changes (3/21) were significantly less frequent than in HSV-I . The diagnosis of viral etiology was confirmed by either elevated virus-specific IgG AI or positive virus PCR. In detail, the virus-specific IgG AI was elevated in all TBE , in 85% of HSV-I , and in 94% of VZV-I . CSF virus PCR was positive in the first diagnostic LP in 0 of 9 (0%) TBE, 14 of 17 (82%) HSV-I, and 11 of 13 (85%) tested VZV-I.Sixteen of the 21 TBE patients (76%) were male, 11 (52%) presented with meningitis, and nine (43%) as meningoencephalitis. Three TBE patients (14%) showed leptomeningeal enhancement upon brain MRI. Electroencephalography (EEG) showed general slow activity in all five (24%) studied patients and epileptiform pattern in one TBE patient. Onset of neurological symptoms in TBE was longer at the time of first diagnostic LP as compared with HSV- and VZV-I (p = 0.007). In general, the CSF cell differentiation revealed a lymphocytic predominance. A markedly increased proportion of neutrophil granulocytes (>20%) was found significantly more often in TBE , compared with 3 (15%) and 1 (6%) patients with HSV-I and VZV-I (p < 0.05 and p < 0.01), respectively. CSF-specific OCB  were found slightly less often in TBE as compared with HSV-I and VZV-I; however, this difference was not significant. An elevated albumin CSF/serum ratio indicating a blood/CSF barrier dysfunction was found in 18 TBE patients (86%), similar to the other two types of CNS infections  , we performed a logistic regression  to analyze if this delay was a confounding factor or caused effect modification. However, the final regression model included only the disease/group variables .CSF analysis at first LP revealed pleocytosis in all patients . Howeverfections . Proof octively) . Upon fon = 12, median 32 pg/mL, range 14–240 pg/mL), below the cut-off shown earlier by us to differentiate between neuroborreliosis and other inflammatory CNS diseases [Two case presentations were particularly demanding in terms of diagnosis: In one patient, CSF analysis performed in the first systemic phase of TBE virus  infection was completely normal. However, later on, the patient developed encephalitis with prominent pleocytosis and showed positive CSF PCR and antibody testing for TBE in the follow-up lumbar puncture. Another patient, a forester with meningitis, showed both positive TBE and Borrelia antibody indices in the first diagnostic lumbar puncture. However, CSF CXCL13 (a B-cell-attracting chemokine) was, as in 11 other TBE cases in this cohort , but are by no means sufficiently dichotomous to confirm or exclude the TBE diagnosis. However, in the first systemic phase (without neurologic deficits) of TBE virus infection, we show that CSF findings can be normal.Because TBE and neuroborreliosis are occupational diseases affecting foresters, an elevated borrelia CSF-serum antibody index as a result of a current or previous neuroborreliosis can be expected to occur more often in patients with TBE. Our findings are consistent with previous data suggesting that CSF CXCL13 levels might differentiate between TBE and neuroborreliosis in such cases, because none of the TBE CSF-serum pairs with CXCL13 values available showed levels exceeding the cut-off previously defined by us for neuroborreliosis .In conclusion, in clinically suspected cases, the determination of TBE antibodies in CSF and serum should be performed, especially if granulocytes and an intrathecal IgM synthesis in CSF are present. These findings may contribute to distinguish TBE from other viral CNS infections, as well as in areas where the disease is not yet common, and to avoid unnecessary medication as well as associated side effects.


Surface electromyography (sEMG) is frequently used to assess muscle activation in older individuals. Subcutaneous fat is one well-known factor that influences sEMG amplitude. The amount of intramuscular fat (IMAT) may negatively impact the muscles ability to produce force with aging, while high density lean tissue  has an opposite effect. However, influence of IMAT or HDL on sEMG amplitude remains unclear. Thus, the aim was to investigate the influence of IMAT and HDL on sEMG amplitude of the gluteus medius (GM) muscle during a maximal voluntary isometric contraction (MVIC) in older adults. Twelve older adults  underwent a CT scan to determine IMAT and HDL cross-sectional area in the GM. IMAT and HDL were normalized as a percentage of the total muscle area. Maximal hip abduction MVIC was measured at 30□ hip abduction in standing, while sEMG was recorded from the GM muscle. Spearman correlations showed a positive association between GM HDL and sEMG amplitude  and negative between GM IMAT and sEMG amplitude . This is the first study to demonstrate the amount of IMAT may limit the ability to activate the hip abductor muscle. Given that muscle activation is a determinant of strength, interventions to lower levels of IMAT and increase levels of lean muscle may be important to slowing decreases in strength with aging.


Human heart samples from the Sydney Heart Bank have become a de facto standard against which others can be measured. Crucially, the heart bank contains a lot of donor heart material: for most researchers this is the hardest to obtain and yet is necessary since we can only study the pathological human heart in comparison with a control, preferably a normal heart sample. It is not generally realised how important the control is for human heart studies. We review our studies on donor heart samples. We report the results obtained with 17 different donor samples collected from 1994 to 2011 and measured from 2005 to 2015 by our standard methodology for in vitro motility and troponin I phosphorylation measurements. The donor heart sample parameters are consistent between the hearts, over time and with different operators indicating that Sydney Heart Bank donor hearts are a valid baseline control for comparison with pathological heart samples. We also discuss to what extent donor heart samples are representative of the normal heart.The online version of this article (10.1007/s12551-020-00740-2) contains supplementary material, which is available to authorized users. It is a great pleasure to contribute to this special issue celebrating the achievements of Cris Dos Remedios and to celebrate his unique creation— the Sydney Heart Bank.This story starts in Berlin in September 2000. I had known Cris as a biophysicist for as long as I can remember. The European Muscle Congress was held in Berlin for the first time in 2000—an age when PowerPoint was a new and risky mode of presentation. After the meeting finished, we found ourselves at a loose end waiting for evening flights and trains and went for a late lunch at the Potsdamer Platz. During our conversation, Cris revealed that he had been collecting human hearts from transplant operations in Sydney.This was a great surprise to me and a pleasant one as well. A couple of years prior, I had started a project to apply our in vitro motility assay to the contractile proteins from human hearts. Ian Purcell, then an MD student, had been able to obtain a small amount of fresh heart tissue from transplant operations at the Freeman Hospital in Newcastle. We had a few end-stage failing samples and one donor sample. Cris said that he had dozens of samples, including donor hearts already and was continuously adding to the collection; moreover, he was willing to supply such samples to anyone who could make good use of them.We immediately came to an agreement to work on these heart samples with our in vitro assays, and a month later, Cris sent us 5 1-g vials each of 5 donor hearts and 5 end-stage failing hearts. These were the basis of Andrew Messer’s thesis and many publications since.The samples that Cris provided then and later were essential for the work we did for the next 15 years. The key merits of the Sydney Heart Bank are that the material is abundant, both in quantity per heart and number of hearts, that the collection regime is of the highest quality with very prompt freezing and storing in liquid nitrogen and that it is shared with the scientific community worldwide. This last point is crucial: there are a significant number of reports on human heart tissue, but they mainly use ‘private’ tissue collections; consequently, there is no way of independently checking whether such results are valid—a fundamental requirement in any scientific investigation.Cris’ generosity in sharing his samples is outstanding, such that his samples have become a sort of de facto standard against which others can be measured. This has been well documented in recent publications  as illustrated in Fig. The variabilities between reported values do not correlate with the sample nor does it correlate with the operator. A statistical analysis of Messer’s data  with known mutations, have clear and reproducible differences from donor heart, implicitly indicating that the donor heart is an acceptable control.2+-sensitivity using the same techniques with many samples over many years clearly demonstrates that donor samples from the Sydney Heart Bank do indeed have uniform properties. Therefore, it is valid to use these samples as controls for comparative experiments  is the nearest to a standard state as could be defined. Applying such a criterion to the Sydney Heart Bank samples would suggest they are unlikely to be normal. The cause of brain death in these patients varied, time on life support varied from 20 to 135 h and times in cardioplegia also varied Smith . The argIt is well known that subarachnoid haemorrhage, stroke and trauma all cause markedly elevated catecholamine levels, and this may be increased again at the time of organ harvest .


In childhood leukemias the central nervous system (CNS) can be invaded by leukemic cells, leading to disease recurrence and treatment failures. Analysis of the cerebrospinal fluid (CSF), which surrounds the brain and spinal cord, is crucial for detection of leukemia in that compartment. Despite advances made in treatments for childhood leukemias, therapies continue to adversely affect the developing brain with resulting neurocognitive deficits in many survivors. This review presents an overview of studies demonstrating that CSF proteins, nucleic acids and metabolites, so called biomarkers, can be utilized in tracing both CNS disease and neurotoxicity of treatments in childhood leukemias.Involvement of the central nervous system (CNS) in childhood leukemias remains a major cause of treatment failures. Analysis of the cerebrospinal fluid constitutes the most important diagnostic pillar in the detection of CNS leukemia and relies primarily on cytological and flow-cytometry studies. With increasing survival rates, it has become clear that treatments for pediatric leukemias pose a toll on the developing brain, as they may cause acute toxicities and persistent neurocognitive deficits. Preclinical research has demonstrated that established and newer therapies can injure and even destroy neuronal and glial cells in the brain. Both passive and active cell death forms can result from DNA damage, oxidative stress, cytokine release, and acceleration of cell aging. In addition, chemotherapy agents may impair neurogenesis as well as the function, formation, and plasticity of synapses. Clinical studies show that neurocognitive toxicity of chemotherapy is greatest in younger children. This raises concerns that, in addition to injury, chemotherapy may also disrupt crucial developmental events resulting in impairment of the formation and efficiency of neuronal networks. This review presents an overview of studies demonstrating that cerebrospinal fluid biomarkers can be utilized in tracing both CNS disease and neurotoxicity of administered treatments in childhood leukemias. The brain and spinal cord are immersed in cerebrospinal fluid (CSF), which remains in close contact with the interstitial fluid, the leptomeninges, and the choroid plexus, and can be altered in the context of central nervous system (CNS) pathology. CSF hypothesis-driven biomarker research, which has also utilized sophisticated screening multiomics technologies, such as proteomics, metabolomics, and transcriptomics , offers Central nervous system involvement in childhood leukemia is rare at initial presentation 3–5%) –5% 3,4,,7,8 but ,8 but 7.MLL or KMT2A)-rearranged cytogenetics [SCD) positivity and increased secreted phosphoprotein 1 or osteopontin (SPP1) expression. The presence of this subpopulation of B cell precursor-ALL cells with a “CNS protein profile” in bone marrow aspirates at diagnosis is strongly associated with isolated CNS relapse. Multiple adhesion molecules, chemokines and their receptors, interleukins and their receptors, protein kinases, and growth factors have been implicated in migration, adhesion, and survival of leukemic cells in the CNS [Historically, with the improved success in controlling systemic disease, CNS involvement, which underlies the propensity of leukemias to relapse, has moved to the frontline . Predispgenetics ,14,15. Igenetics , it was  the CNS . The gold standard technology used to evaluate for CNS disease is the detection of leukemic cells in the cerebrospinal fluid (CSF) after lumbar puncture by means of routine cytology ,8,17. HoThe crucial observation that most CNS relapses occur in patients initially diagnosed as CNS-negative highlights the urgent need for more sensitive diagnostic and surveillance approaches . Novel sOmans and colleagues  used terThe yield for detecting leukemic cells within the CSF increases with the use of multi-color flow cytometry utilizing B- and T-cell markers, as demonstrated by several groups of investigators ,24,25,26IgH and TCR genes, minimal residual disease (MRD) was detected in the CSF in 46.8% of children with ALL with no puncture accident of morphological CNS involvement [IgH/TCR gene derangements in bone marrow aspirates. In patients with CNS MRD treated with a less intensive protocol (GBTLI-ALL-93), significantly lower 5-year event-free survival was demonstrated. Similar findings were reported by Scridelli and colleagues [Using polymerase chain reaction (PCR) with homo/heteroduplex analysis utilizing consensus primers for olvement . All patlleagues . In thislleagues . MicroRNAs (miRs) are highly conserved small non-coding RNAs that are involved in orchestration of proliferation, differentiation, and survival . AlteredmiRs in childhood leukemias have mainly been studied in blood or bone marrow aspirates. Studies analyzing miRs in the CSF of children with leukemia are scarce. Egyed and colleagues  hypothesOther leukemia-associated factors released into the extracellular space and present in the CSF include soluble L-selectin (sL-selectin) , interlesIL2Rα is released along with interleukin-2 from activated T-cells. In a study of 77 pediatric patients with ALL, Lee and coinvestigators analyzed both CSF and serum samples . The groVascular endothelial growth factor A (VEGF-A) is highly expressed in solid tumors. It binds to its soluble membrane receptors sVEGFR1 and sVEGFR2. sVEGFRs block tumor promoting activities of VEGF-A. Tang and colleagues investigated sVEGFR1 and R2 as biomarkers in CNS leukemia in CSF and serum samples of 35 patients with ALL with or without CNS disease . sVEGFR1Another potentially interesting biomarker for CNS leukemia is osteopontin, a protein secreted by many cells, including activated T-cells, natural killer cells, and tumor cells. Osteopontin, also known as early T-cell activation gene-1 (SPP1 or ETA-1), is a matricellular protein expressed primarily in the bone marrow. It is produced by osteoblasts, osteoclasts, and other malignant and non-malignant cells and is found as a full-length molecule of transcriptionally processed variants . It binThe relationship between CSF osteopontin levels and CNS leukemia was evaluated in 62 pediatric patients with acute leukemia and 16 controls . CSF ostEvaluation of multiplexed biomarkers for assessment of CSF infiltration in pediatric ALL has been attempted for matrix metalloproteinase 9 (MMP-9), monocyte chemotactic protein (CCL-2), soluble vascular cell adhesion molecule-1 (sVCAM-1), interferon gamma (IFN-γ), and inducible protein 10 . An assoIn addition to the above hypothesis-driven studies, recent advances in proteomics technologies have stimulated interest in the application of mass spectrometry (MS) in qualitative and quantitative analysis of the CSF proteome, in an attempt to better trace the development of CNS leukemia in children and its response to treatment. Advancements in the resolution, mass accuracy, sensitivity and scan rate of mass spectrometers for protein analysis, including label-free and stable isotope labeling approaches, have enabled these types of studies. The label-free strategy injects individual samples directly into the mass spectrometer and quantifies the relative abundance of peptides ,47,48. UREACTOME pathway analysis revealed that the differentially expressed genes were associated with a total of 189 pathways . The autNeurocognitive morbidity is frequent in childhood cancer survivors ,54,55,56Lower performance IQ scores compared to controls are most often detected if polychemotherapy is initiated prior to the sixth year of life . LeukoenWith the help of preclinical and clinical translational research, knowledge of how chemotherapy impacts the pediatric brain has made significant progress, yet many gaps remain. Modern neuroimaging techniques have helped discover the presence of white (WM) and grey matter (GM) changes, some of which may be reversible and others may persist ,71,72,73Furthermore, adult survivors of ALL were shown to have smaller volumes of grey matter, in particular in the hippocampus, amygdala, thalamus, and nucleus accumbens, which interestingly correlated with lower hippocampal memory performance  and smalIn an attempt to understand how chemotherapy affects the brain and which, if any, CSF biomarkers might help prognosticate neurocognitive outcomes, researchers have used both hypothesis-driven approaches and, more recently, proteomics platforms. Interestingly, changes of selected CSF biomarkers during chemotherapy have been found to correlate with future neurocognitive outcomes .Oesterlundh and colleagues analyzed neurochemical markers of brain injury in CSF during induction treatment for acute ALL in children and reported significant increases in the levels of the neuronal marker neuron-specific-enolase (NSE), the astroglial marker glial fibrillary acidic protein (GFAP), and the axonal marker neurofilament protein light chain  . An incrIn the context of high dose systemic methotrexate treatment in children with ALL, plasma methotrexate levels correlated with increase in the CSF activity of beta-glucuronidase, which could have resulted from leakage of this enzyme from injured or degenerating brain cells . Induction chemotherapy may lead to elevated CSF levels of tau, phospho-tau, and neuromodulin. Of these proteins, tau concentrations were found to inversely correlate with future IQ performance ,88. CSF Markers of oxidative stress in the CNS, in particular high concentrations of oxidized CSF phospholipids, were also found to correlate with neurobehavioral problems   and cognIn a large study by Cheung and coinvestigators , 235 patMoore and colleagues  analyzedThese hypothesis-driven research studies have demonstrated that cellular injury, oxidative stress, and inflammation occur in the CNS in the context of chemotherapy for childhood leukemias and that CSF biomarkers reflecting these processes may be useful in identifying individuals at risk for worse neurologic outcomes.In an attempt to discover novel biomarkers that may help trace further pathomechanisms of chemotherapy effects on the brain, proteomics platforms have been utilized. Yu and colleagues  attempteDiscovering a relationship between identified protein changes in the CSF and pathways that mediate neurotoxic effects of treatment for ALL is a very challenging task. Given that the blood–brain barrier, the blood–CSF barrier and the blood–leptomeningeal barrier can be compromised during cancer chemotherapy and systemic proteins may be allowed to enter the CSF space, alterations measured in the CSF are most likely multifactorial and may reflect consequences of (1) the demise of CNS leukemic cells, (2) the demise of systemic leukemic cells, (3) toxicity of treatment on organs other than the CNS, and (4) toxicity of treatment on the CNS itself. In an attempt to select candidate biomarkers indicative of CNS toxicity, Yu and colleagues identified those proteins that are highly expressed in the brain. Of those, neural cell adhesion molecule 2 (NCAM2) and neuronal cell adhesion molecule (NRCAM), both of which are critical for neural cell adhesion, cell–cell interactions during synaptogenesis, and plasticity ,103, incNeuronal growth regulator 1 (NEGR1) and secretogranin-3 (SCG-3) were also significantly elevated at week 5 and weeks 10–14 respectively. NEGR1 controls neuronal cell growth and differentiation , and SCGThus, this proteomics approach helped identify interesting protein species that suggest impaired synaptogenesis and synaptic plasticity as new potential mechanisms of chemotherapy-related CNS toxicity. Whether these proteins might represent biomarkers for long-term neurocognitive outcomes will need to be investigated in further studies, which will correlate CSF protein alterations with the results of neuropsychological assessments. Brown and colleagues  utilizedCD19-directed chimeric antigen receptor (CAR)-T cell therapy has recently been adopted in the treatment of childhood leukemias ,108. AftResearch on CSF biomarkers for detection of leukemic invasion and for tracing toxicity of treatment in the CNS has experienced remarkable progress in the past 20 years. In addition to a priori hypothesis-driven approaches, technological advances in multiomics methods, in particular sophisticated proteomics platforms, have enabled non-hypothesis-driven analysis of CSF. Insights gained from first pilot studies provide an excellent foundation for further investigations attempting to identify the role of specific proteins and biological pathways in CNS infiltration with leukemic cells on the one hand and, on the other, to understand the pathomechanisms of brain injury caused by the evolving treatments of childhood leukemias.All biomarkers mentioned in this review are still in the discovery phase. Candidate CSF biomarkers capable of reflecting CNS disease progression, CNS response to therapeutic interventions, or predicting long-term neurocognitive outcomes must undergo a rigorous process of verification, clinical validation for multiple purposes, and multicenter validation for clinical purposes before they can reach the phase of clinical implementation .