Age-related gait standards for healthy children and young people: the GOS-ICH paediatric gait centiles

Objective To develop paediatric gait standards in healthy children and young people. Methods This observational study builds on earlier work to address the lack of population standards for gait measurements in children. Analysing gait in children affected by neurological or musculoskeletal conditions is an important component of paediatric assessment but is often confounded by developmental changes. The standards presented here do not require clinician expertise to interpret and offer an alternative to developmental tables of normalised gait data. Healthy children aged 1-19 years were recruited from community settings in London and Hertfordshire, U.K. The GAITRite ® walkway was used to record measurements for each child for velocity, cadence, step length, base of support, and stance, single and double support (as percentage of gait cycle). We fitted generalized linear additive models for location, scale and shape (gamlss). Results We constructed percentile charts for seven gait variables measured on 624 (321 males) contemporary healthy children using gamlss package in R. A clinical application of gait standards was explored. Conclusion Age-related, gender-specific standards for seven gait variables were developed and are presented here. They have a familiar format and can be used clinically to aid diagnoses, and to monitor change over time for both medical therapy and natural history of the condition. The clinical example demonstrates the potential of the GOS-ICH Paediatric Gait Centiles (GOS-ICH PGC) to enable meaningful interpretation of change in an individual’s performance, and describes characteristic features of gait from a specific population throughout childhood.Peer reviewedFinal Accepted Versio

Opposing shear senses in a subdetachment mylonite zone: Implications for core complex mechanics

[1] Global studies of metamorphic core complexes and low‐angle detachment faults have highlighted a fundamental problem: Since detachments excise crustal section, the relationship between the mylonitic rocks in their footwalls and the brittle deformation in their hanging walls is commonly unclear. Mylonites could either reflect ductile deformation related to exhumation along the detachment fault, or they could be a more general feature of the extending middle crust that has been “captured ” by the detachment. In the first case we would expect the kinematics of the mylonite zone to mirror the sense of movement on the detachment; in the second case both the direction and sense of shear in the mylonites could be different. The northern Snake Range décollement (NSRD) is a classic Basin and Range detachment fault with a well‐documented top‐east of displacement. We present structural, paleo-magnetic, geochronological, and geothermometric evidence to suggest that the mylonite zone below the NSRD locally experienced phases of both east ‐ and west‐directed shear, inconsistent with movement along a single detachment fault. We therefore propose that the footwall mylonites represent a predetachment dis-continuity in the middle crust that separated localized deformation above from distributed crustal flow below (localized‐distributed transition (LDT)). The mylonites were subsequently captured by a moderately dipping brittle detachment that soled down to the middle crust and exhumed them around a rolling hinge into a subhorizontal orientation at the surface, produc-ing the present‐day NSRD. In this interpretation the brittle hanging wall represents a series of rotated upper crustal normal faults, whereas the mylonitic footwall represents one or more exhumed middl

Rheological transitions in the middle crust:insights from Cordilleran metamorphic core complexes

High-strain mylonitic rocks in Cordilleran metamorphic core complexes reflect ductile deformation in the middle crust, but in many examples it is unclear how these mylonites relate to the brittle detachments that overlie them. Field observations, microstructural analyses, and thermobarometric data from the footwalls of three metamorphic core complexes in the Basin and Range Province, USA (the Whipple Mountains, California; the northern Snake Range, Nevada; and Ruby Mountains–East Humboldt Range, Nevada), suggest the presence of two distinct rheological transitions in the middle crust: (1) the brittle–ductile transition (BDT), which depends on thermal gradient and tectonic regime, and marks the switch from discrete brittle faulting and cataclasis to continuous, but still localized, ductile shear, and (2) the localized–distributed transition, or LDT, a deeper, dominantly temperature-dependent transition, which marks the switch from localized ductile shear to distributed ductile flow. In this model, brittle normal faults in the upper crust persist as ductile shear zones below the BDT in the middle crust, and sole into the subhorizontal LDT at greater depths.<br><br>In metamorphic core complexes, the presence of these two distinct rheological transitions results in the development of two zones of ductile deformation: a relatively narrow zone of high-stress mylonite that is spatially and genetically related to the brittle detachment, underlain by a broader zone of high-strain, relatively low-stress rock that formed in the middle crust below the LDT, and in some cases before the detachment was initiated. The two zones show distinct microstructural assemblages, reflecting different conditions of temperature and stress during deformation, and contain superposed sequences of microstructures reflecting progressive exhumation, cooling, and strain localization. The LDT is not always exhumed, or it may be obscured by later deformation, but in the Whipple Mountains, it can be directly observed where high-strain mylonites captured from the middle crust depart from the brittle detachment along a mylonitic front

1H NMR-Linked Metabolomics Analysis of Liver from a Mouse Model of NP-C1 Disease

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link

Synthesis and study of novel multifunctional cyclodextrin‐deferasirox hybrids

Metal dyshomeostasis is central to a number of disorders that result from, inter alia, oxidative stress protein misfolding, and cholesterol dyshomeostasis. In this respect, metal deficiencies are usually readily corrected by treatment with supplements, whereas metal overload can be overcome by the use of metal‐selective chelation therapy. Deferasirox, 4‐[(3Z,5E)‐3,5‐bis(6‐oxo‐1‐cyclohexa‐2,4‐dienylidene)‐1,2,4‐triazolidin‐1‐yl]benzoic acid, Exjade, or ICL670, is used clinically to treat hemosiderosis (iron overload), which often results from multiple blood transfusions. Cyclodextrins are cyclic glucose units that are extensively used in the pharmaceutical industry as formulating agents as well as for encapsulating hydrophobic molecules such as in the treatment of Niemann Pick C or for hypervitaminosis. We have conjugated deferasirox, via an amide coupling reaction, to both 6A‐amino‐6A‐deoxy‐β‐cyclodextrin and 3A‐amino‐3A‐deoxy‐2A(S),3A(R)‐β‐cyclodextrin, at the upper and lower rim respectively creating hybrid molecules with dual properties, capable of both metal chelation and cholesterol encapsulation. Our findings emphasize the importance of the conjugation of β‐cyclodextrin with deferasirox to significantly improve the biological properties and reduce the cytotoxicity of this drug

Combined anti-inflammatory and neuroprotective treatments have the potential to impact disease phenotypes in Cln3−/− mice

Batten disease, or juvenile NCL, is a fatal neurodegenerative disorder that occurs due to mutations in the CLN3 gene. Because the function of CLN3 remains unclear, experimental therapies for JNCL have largely concentrated upon the targeting of downstream pathomechanisms. Neuron loss is preceded by localized glial activation, and in this proof-of-concept study we have investigated whether targeting this innate immune response with ibuprofen in combination with the neuroprotective agent lamotrigine improves the previously documented beneficial effects of immunosuppressants alone. Drugs were administered daily to symptomatic Cln3 -/- mice over a 3 month period, starting at 6 months of age, and their impact was assessed using both behavioral and neuropathological outcome measures. During the treatment period, the combination of ibuprofen and lamotrigine significantly improved the performance of Cln3 -/- mice on the vertical pole test, slowing the disease-associated decline, but had less of an impact upon their rotarod performance. There were also moderate and regionally dependent effects upon astrocyte activation that were most pronounced for ibuprofen alone, but there was no overt effect upon microglial activation. Administering such treatments for longer periods will enable testing for any impact upon the neuron loss that occurs later in disease progression. Given the partial efficacy of these treatments, it will be important to test further drugs of this type in order to find more effective combinations

The sensitivity of murine spermiogenesis to miglustat is a quantitative trait: a pharmacogenetic study

BACKGROUND: A major event in the post-meiotic development of male germ cells is the formation of the acrosome. This process can be perturbed in C57BL/6 mice by administration of the small molecule miglustat (N-butyldeoxynojirimycin, NB-DNJ). The miglustat-treated mice produce morphologically abnormal spermatozoa that lack acrosomes and are poorly motile. In C57BL/6 mice, miglustat can be used to maintain long-term reversible infertility. In contrast, when miglustat was evaluated in normal men, it did not affect spermatogenesis. To gain more insight into this species difference we have now evaluated the reproductive effects of miglustat in rabbits, in multiple mouse strains and in interstrain hybrid mice. METHODS: Male mice of 18 inbred strains were administered miglustat orally or via miniosmotic pumps. Rabbits were given the compound in their food. Fourth-generation interstrain hybrid mice, bred from C57BL/6 and FVB/N mice (which differ in their response to miglustat), also received the drug. Data on fertility (natural mating), sperm motility and morphology, acrosome status, and serum drug levels were collected. RESULTS: In rabbits the drug did not induce aberrations of sperm shape or motility, although the serum level of miglustat in rabbits far exceeded the level in C57BL/6 mice (8.4 μM and 0.5 μM, respectively). In some strains of the Swiss and Castle lineages of inbred mice miglustat did not cause infertility, severe morphological sperm aberrations or reduced sperm motility. In these strains miglustat only had milder effects. However, miglustat strongly disturbed acrosome and sperm nucleus development in AKR/J and BALB/c mice and in a number of C57BL/6-related strains. The consequences of drug administration in the interstrain hybrid mice were highly variable. Judging by the number of grossly abnormal spermatozoa, these genetically heterogeneous mice displayed a continuous range of intermediate responses, distinct from either of their parental strains. CONCLUSION: The effects of miglustat on spermatogenesis in mice are strain-dependent, while in rabbits the drug is ineffective. Evaluation of interstrain hybrid mice indicated that the sensitivity of spermatogenesis to miglustat is a quantitative trait. These studies pave the way for identifying the genetic factors underlying the strain/species differences in the effect of miglustat

Porcine iGb3s gene silencing provides minimal benefit for clinical xenotransplantation

Background The Galα(1,3)Gal epitope (α-GAL), created by α-1,3-glycosyltransferase-1 (GGTA1), is a major xenoantigen causing hyperacute rejection in pig-to-primate and pig-to-human xenotransplantation. In response, GGTA1 gene-deleted pigs have been generated. However, it is unclear whether there is a residual small amount of α-Gal epitope expressed in GGTA1−/− pigs. Isoglobotrihexosylceramide synthase (iGb3s), another member of the glycosyltransferase family, catalyzes the synthesis of isoglobo-series glycosphingolipids with an α-GAL-terminal disaccharide (iGb3), creating the possibility that iGb3s may be a source of α-GAL epitopes in GGTA1−/− animals. The objective of this study was to examine the impact of silencing the iGb3s gene (A3GalT2) on pig-to-primate and pig-to-human immune cross-reactivity by creating and comparing GGTA1−/− pigs to GGTA1−/−- and A3GalT2−/−-double-knockout pigs. Methods We used the CRISPR/Cas 9 system to target the GGTA1 and A3GalT2 genes in pigs. Both GGTA1 and A3GalT2 genes are functionally inactive in humans and baboons. CRISPR-treated cells used directly for somatic cell nuclear transfer produced single- and double-gene-knockout piglets in a single pregnancy. Once grown to maturity, the glycosphingolipid profile (including iGb3) was assayed in renal tissue by normal-phase liquid chromatography. In addition, peripheral blood mononuclear cells (PBMCs) were subjected to (i) comparative cross-match cytotoxicity analysis against human and baboon serum and (ii) IB4 staining for α-GAL/iGb3. Results Silencing of the iGb3s gene significantly modulated the renal glycosphingolipid profile and iGb3 was not detected. Moreover, the human and baboon serum PBMC cytotoxicity and α-GAL/iGb3 staining were unchanged by iGb3s silencing. Conclusions Our data suggest that iGb3s is not a contributor to antibody-mediated rejection in pig-to-primate or pig-to-human xenotransplantation. Although iGb3s gene silencing significantly changed the renal glycosphingolipid profile, the effect on Galα3Gal levels, antibody binding, and cytotoxic profiles of baboon and human sera on porcine PBMCs was neutral

Imaging of changes in copper trafficking and redistribution in a mouse model of Niemann-Pick C disease using positron emission tomography

Niemann-Pick C disease (NPC) is an autosomal recessive lysosomal storage disorder resulting from mutations in the NPC1 (95% of cases) or NPC2 genes. Disturbance of copper homeostasis has been reported in NPC1 disease. In this study we have used whole-body positron emission tomography (PET) and brain electronic autoradiography with copper-64 (64Cu), in the form of the copper(II) bis(thiosemicarbazonato) complex 64Cu-GTSM, to image short-term changes in copper trafficking after intravenous injection in a transgenic mouse model of NPC1 disease. 64Cu-GTSM is taken up in all tissues and dissociates rapidly inside cells, allowing monitoring of the subsequent efflux and redistribution of 64Cu from all tissues. Significantly enhanced retention of 64Cu radioactivity was observed in brain, lungs and blood at 15 h post-injection in symptomatic Npc1−/− transgenic mice compared to wildtype controls. The enhanced retention of 64Cu in brain was confirmed by electronic autoradiography, particularly in the midbrain, thalamus, medulla and pons regions. Positron emission tomography imaging with 64Cu in selected chemical forms could be a useful diagnostic and research tool for the management and understanding of NPC1 disease

A novel, highly sensitive and specific biomarker for Niemann-Pick type C1 disease

Background Lysosomal storage disorders (LSDs), are a heterogeneous group of rare disorders caused by defects in genes encoding for proteins involved in the lysosomal degradation of macromolecules. They occur at a frequency of about 1 in 5,000 live births, though recent neonatal screening suggests a higher incidence. New treatment options for LSDs demand a rapid, early diagnosis of LSDs if maximal clinical benefit is to be achieved. Methods Here, we describe a novel, highly specific and sensitive biomarker for Niemann-Pick Type C disease type 1 (NPC1), lyso-sphingomyelin-509. We cross-validate this biomarker with cholestane-3β,5α,6β-triol and relative lysosomal volume. The primary cohort for establishment of the biomarker contained 135 NPC1 patients, 66 NPC1 carriers, 241 patients with other LSDs and 46 healthy controls. Results With a sensitivity of 100.0% and specificity of 91.0% a cut-off of 1.4 ng/ml was established. Comparison with cholestane-3β,5α,6β-triol and relative acidic compartment volume measurements were carried out with a subset of 125 subjects. Both cholestane-3β,5α,6β-triol and lyso-Sphingomyelin-509 were sufficient in establishing the diagnosis of NPC1 and correlated with disease severity. Conclusion In summary, we have established a new biomarker for the diagnosis of NPC1, and further studies will be conducted to assess correlation to disease progress and monitoring treatment