112 research outputs found

    Association of maternal levothyroxine use during pregnancy with offspring birth and neurodevelopmental outcomes: a population-based cohort study

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    BACKGROUND: The influence of maternal levothyroxine treatment during pregnancy remains unclear. This study aimed to evaluate the associations of maternal levothyroxine treatment during pregnancy with the birth and neurodevelopmental outcomes in offspring. METHODS: This population-based cohort study was conducted among pregnant women using the Hong Kong Clinical Data Analysis and Reporting System. Mother-child pairs in Hong Kong from 2001 to 2015 were included and children were followed up till 2020. We defined the exposure group as mothers who were exposed to levothyroxine during pregnancy. Preterm birth and small for gestational age (SGA) were included as birth outcomes. Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) were included as neurodevelopmental outcomes. Odds ratios (OR) or hazard ratios (HRs) with a 95% confidence interval (CI) were evaluated to assess the association of gestational levothyroxine use with offspring birth and neurodevelopmental outcomes respectively, using propensity score fine-stratification weighting and a Cox proportional hazards regression model. RESULTS: Among 422,156 mother-child pairs, 2125 children were born from mothers exposed to levothyroxine during pregnancy. A significantly increased risk of preterm birth was observed in children with maternal levothyroxine exposure during pregnancy, when compared to mothers who had no history of thyroid-related diagnoses or prescriptions (weighted OR [wOR]: 1.22, 95% CI: 1.07, 1.39). Similarly, an increased risk of preterm birth was found among children of gestational levothyroxine users, when compared to children of mothers who had used levothyroxine before but stopped during pregnancy (wOR: 2.16, 95% CI: 1.09, 4.25). Sensitivity analysis, by excluding mothers exposed to psychotropic or antiepileptic medications before or during pregnancy, also indicated a similar increased risk of preterm birth regarding the gestational use of levothyroxine (wOR: 1.26, 95% CI: 1.10, 1.45). No significant association was observed for the risk of SGA, ADHD, and ASD. CONCLUSIONS: There is no evidence that gestational use of levothyroxine is associated with SGA, ADHD, or ASD in offspring. Gestational levothyroxine treatment is associated with a higher risk of preterm birth. Such risk might be confounded by the underlying maternal thyroid disease itself, however, we cannot completely exclude the possible effect of gestational L-T4 treatment on offspring preterm birth. Our findings provided support to the current guidelines on the cautious use of levothyroxine treatment during pregnancy. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12916-022-02586-9

    Pulse wave velocity is associated with increased plasma oxLDL in ageing but not with FGF21 and habitual exercise

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    Fibroblast growth factor 21 (FGF21) and adiponectin increase expression of genes involved in antioxidant pathways, but their roles in mediating oxidative stress and arterial stiffness with ageing and habitual exercise remain unknown. We explored the role of the FGF21–adiponectin axis in mediating oxidative stress and arterial stiffness with ageing and habitual exercise. Eighty age- and sex-matched healthy individuals were assigned to younger sedentary or active (18–36 years old,n=20 each) and older sedentary or active (45–80 years old,n=20 each) groups. Arterial stiffness was measured indirectly using pulse wave velocity (PWV). Fasted plasma concentrations of FGF21, adiponectin and oxidized low-density lipoprotein (oxLDL) were measured. PWV was 0.2-fold higher and oxLDL concentration was 25.6% higher (both p<0.001) in older than younger adults, despite no difference in FGF21 concentration (p=0.097) between age groups. PWV (p=0.09) and oxLDL concentration (p=0.275) did not differ between activity groups but FGF21 concentration was 9% lower in active than sedentary individuals (p=0.011). Adiponectin concentration did not differ by age (p=0.642) or exercise habits (p=0.821). In conclusion, age, but not habitual exercise, was associated with higher oxidative stress and arterial stiffness. FGF21 and adiponectin did not differ between younger and older adults, unlikely mediating oxidative stress and arterial stiffness in healthy adults. <br

    Adaptive Mutations in the JC Virus Protein Capsid Are Associated with Progressive Multifocal Leukoencephalopathy (PML)

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    PML is a progressive and mostly fatal demyelinating disease caused by JC virus infection and destruction of infected oligodendrocytes in multiple brain foci of susceptible individuals. While JC virus is highly prevalent in the human population, PML is a rare disease that exclusively afflicts only a small percentage of immunocompromised individuals including those affected by HIV (AIDS) or immunosuppressive drugs. Viral- and/or host-specific factors, and not simply immune status, must be at play to account for the very large discrepancy between viral prevalence and low disease incidence. Here, we show that several amino acids on the surface of the JC virus capsid protein VP1 display accelerated evolution in viral sequences isolated from PML patients but not in sequences isolated from healthy subjects. We provide strong evidence that at least some of these mutations are involved in binding of sialic acid, a known receptor for the JC virus. Using statistical methods of molecular evolution, we performed a comprehensive analysis of JC virus VP1 sequences isolated from 55 PML patients and 253 sequences isolated from the urine of healthy individuals and found that a subset of amino acids found exclusively among PML VP1 sequences is acquired via adaptive evolution. By modeling of the 3-D structure of the JC virus capsid, we showed that these residues are located within the sialic acid binding site, a JC virus receptor for cell infection. Finally, we go on to demonstrate the involvement of some of these sites in receptor binding by demonstrating a profound reduction in hemagglutination properties of viral-like particles made of the VP1 protein carrying these mutations. Collectively, these results suggest that a more virulent PML causing phenotype of JC virus is acquired via adaptive evolution that changes viral specificity for its cellular receptor(s)

    Generation of subject-specific, dynamic, multisegment ankle and foot models to improve orthotic design: a feasibility study

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    ABSTRACT: BACKGROUND: Currently, custom foot and ankle orthosis prescription and design tend to be based on traditional techniques, which can result in devices which vary greatly between clinicians and repeat prescription. The use of computational models of the foot may give further insight in the biomechanical effects of these devices and allow a more standardised approach to be taken to their design, however due to the complexity of the foot the models must be highly detailed and dynamic. METHODS: Functional and anatomical datasets will be collected in a multicentre study from 10 healthy participants and 15 patients requiring orthotic devices. The patient group will include individuals with metarsalgia, flexible flat foot and drop foot. Each participant will undergo a clinical foot function assessment, 3D surface scans of the foot under different loading conditions, and detailed gait analysis including kinematic, kinetic, muscle activity and plantar pressure measurements in both barefoot and shod conditions. Following this each participant will undergo computed tomography (CT) imaging of their foot and ankle under a range of loads and positions while plantar pressures are recorded. A further subgroup of participants will undergo magnetic resonance imaging (MRI) of the foot and ankle. Imaging data will be segmented to derive the size of bones and orientation of the joint axes. Insertion points of muscles and ligaments will be determined from the MRI and CT-scans and soft tissue material properties computed from the loaded CT data in combination with the plantar pressure measurements. Gait analysis data will be used to drive the models and in combination with the 3D surface scans for scaling purposes. Predicted plantar pressures and muscle activation patterns predicted from the models will be compared to determine the validity of the models. DISCUSSION: This protocol will lead to the generation of unique datasets which will be used to develop linked inverse dynamic and forward dynamic biomechanical foot models. These models may be beneficial in predicting the effect of and thus improving the efficacy of orthotic devices for the foot and ankle

    Proteomics analysis of serum protein profiling in pancreatic cancer patients by DIGE: up-regulation of mannose-binding lectin 2 and myosin light chain kinase 2

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    <p>Abstract</p> <p>Background</p> <p>Pancreatic cancer has significant morbidity and mortality worldwide. Good prognosis relies on an early diagnosis. The purpose of this study was to develop techniques for identifying cancer biomarkers in the serum of patients with pancreatic cancer.</p> <p>Methods</p> <p>Serum samples from five individuals with pancreatic cancer and five individuals without cancer were compared. Highly abundant serum proteins were depleted by immuno-affinity column. Differential protein analysis was performed using 2-dimensional differential in-gel electrophoresis (2D-DIGE).</p> <p>Results</p> <p>Among these protein spots, we found that 16 protein spots were differently expressed between the two mixtures; 8 of these were up-regulated and 8 were down-regulated in cancer. Mass spectrometry and database searching allowed the identification of the proteins corresponding to the gel spots. Up-regulation of mannose-binding lectin 2 and myosin light chain kinase 2, which have not previously been implicated in pancreatic cancer, were observed. In an independent series of serum samples from 16 patients with pancreatic cancer and 16 non-cancer-bearing controls, increased levels of mannose-binding lectin 2 and myosin light chain kinase 2 were confirmed by western blot.</p> <p>Conclusions</p> <p>These results suggest that affinity column enrichment and DIGE can be used to identify proteins differentially expressed in serum from pancreatic cancer patients. These two proteins 'mannose-binding lectin 2 and myosin light chain kinase 2' might be potential biomarkers for the diagnosis of the pancreatic cancer.</p

    Repetitive N-WASP–Binding Elements of the Enterohemorrhagic Escherichia coli Effector EspFU Synergistically Activate Actin Assembly

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    Enterohemorrhagic Escherichia coli (EHEC) generate F-actin–rich adhesion pedestals by delivering effector proteins into mammalian cells. These effectors include the translocated receptor Tir, along with EspFU, a protein that associates indirectly with Tir and contains multiple peptide repeats that stimulate actin polymerization. In vitro, the EspFU repeat region is capable of binding and activating recombinant derivatives of N-WASP, a host actin nucleation-promoting factor. In spite of the identification of these important bacterial and host factors, the underlying mechanisms of how EHEC so potently exploits the native actin assembly machinery have not been clearly defined. Here we show that Tir and EspFU are sufficient for actin pedestal formation in cultured cells. Experimental clustering of Tir-EspFU fusion proteins indicates that the central role of the cytoplasmic portion of Tir is to promote clustering of the repeat region of EspFU. Whereas clustering of a single EspFU repeat is sufficient to bind N-WASP and generate pedestals on cultured cells, multi-repeat EspFU derivatives promote actin assembly more efficiently. Moreover, the EspFU repeats activate a protein complex containing N-WASP and the actin-binding protein WIP in a synergistic fashion in vitro, further suggesting that the repeats cooperate to stimulate actin polymerization in vivo. One explanation for repeat synergy is that simultaneous engagement of multiple N-WASP molecules can enhance its ability to interact with the actin nucleating Arp2/3 complex. These findings define the minimal set of bacterial effectors required for pedestal formation and the elements within those effectors that contribute to actin assembly via N-WASP-Arp2/3–mediated signaling pathways

    MAP kinase pathways and calcitonin influence CD44 alternate isoform expression in prostate cancer cells

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    <p>Abstract</p> <p>Background</p> <p>Dysregulated expression and splicing of cell adhesion marker CD44 is found in many types of cancer. In prostate cancer (PC) specifically, the standard isoform (CD44s) has been found to be downregulated compared with benign tissue whereas predominant variant isoform CD44v7-10 is upregulated. Mitogen-activated protein kinase pathways and paracrine calcitonin are two common factors linked to dysregulated expression and splicing of CD44 in cancer. Calcitonin has been found to increase proliferation and invasion in PC acting through the protein kinase A pathway.</p> <p>Methods</p> <p>In androgen-independent PC with known high CD44v7-10 expression, CD44 total and CD44v7-10 RNA or protein were assessed in response to exogenous and endogenous calcitonin and to inhibitors of protein kinase A, MEK, JNK, or p38 kinase. Benign cells and calcitonin receptor-negative PC cells were also tested.</p> <p>Results</p> <p>MEK or p38 but not JNK reduced CD44 total RNA by 40%–65% in cancer and benign cells. Inhibition of protein kinase A reduced CD44 total and v7-10 protein expression. In calcitonin receptor-positive cells only, calcitonin increased CD44 variant RNA and protein by 3 h and persisting to 48 h, apparently dependent on an uninhibited p38 pathway. Cells with constitutive CT expression showed an increase in CD44v7-10 mRNA but a decrease in CD44 total RNA.</p> <p>Conclusion</p> <p>The MEK pathway increases CD44 RNA, while calcitonin, acting through the protein kinase A and p38 pathway, facilitates variant splicing. These findings could be used in the formulation of therapeutic methods for PC targeting CD44 alternate splicing.</p

    COSMIC (Cohort Studies of Memory in an International Consortium): An international consortium to identify risk and protective factors and biomarkers of cognitive ageing and dementia in diverse ethnic and sociocultural groups

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    BACKGROUND: A large number of longitudinal studies of population-based ageing cohorts are in progress internationally, but the insights from these studies into the risk and protective factors for cognitive ageing and conditions like mild cognitive impairment and dementia have been inconsistent. Some of the problems confounding this research can be reduced by harmonising and pooling data across studies. COSMIC (Cohort Studies of Memory in an International Consortium) aims to harmonise data from international cohort studies of cognitive ageing, in order to better understand the determinants of cognitive ageing and neurocognitive disorders. METHODS/DESIGN: Longitudinal studies of cognitive ageing and dementia with at least 500 individuals aged 60 years or over are eligible and invited to be members of COSMIC. There are currently 17 member studies, from regions that include Asia, Australia, Europe, and North America. A Research Steering Committee has been established, two meetings of study leaders held, and a website developed. The initial attempts at harmonising key variables like neuropsychological test scores are in progress. DISCUSSION: The challenges of international consortia like COSMIC include efficient communication among members, extended use of resources, and data harmonisation. Successful harmonisation will facilitate projects investigating rates of cognitive decline, risk and protective factors for mild cognitive impairment, and biomarkers of mild cognitive impairment and dementia. Extended implications of COSMIC could include standardised ways of collecting and reporting data, and a rich cognitive ageing database being made available to other researchers. COSMIC could potentially transform our understanding of the epidemiology of cognitive ageing, and have a world-wide impact on promoting successful ageing

    Asynchronous combinatorial action of four regulatory factors activates Bcl11b for T cell commitment

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    During T cell development, multipotent progenitors relinquish competence for other fates and commit to the T cell lineage by turning on Bcl11b, which encodes a transcription factor. To clarify lineage commitment mechanisms, we followed developing T cells at the single-cell level using Bcl11b knock-in fluorescent reporter mice. Notch signaling and Notch-activated transcription factors collaborate to activate Bcl11b expression irrespectively of Notch-dependent proliferation. These inputs work via three distinct, asynchronous mechanisms: an early locus 'poising' function dependent on TCF-1 and GATA-3, a stochastic-permissivity function dependent on Notch signaling, and a separate amplitude-control function dependent on Runx1, a factor already present in multipotent progenitors. Despite their necessity for Bcl11b expression, these inputs act in a stage-specific manner, providing a multitiered mechanism for developmental gene regulation
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