20 research outputs found

    Clinically Unapparent Infantile Thiamin Deficiency in Vientiane, Laos

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    Infantile beriberi, or clinical thiamin (vitamin B1) deficiency in infants, is a forgotten disease in Asia, where 100 years ago it was a major public health problem. Infants with this deficiency, commonly aged ∼ 2–3 months, present in cardiac failure but usually rapidly improve if given thiamin injections. It remains relatively common in Vientiane, Lao PDR (Laos), probably because of prolonged intra- and post-partum food avoidance behaviours. Clinical disease may be the tip of an iceberg with subclinical thiamin deficiency contributing to sickness in infants without overt clinical beriberi. We therefore recruited 778 sick infants admitted during one year at Mahosot Hospital, Vientiane, without clinical evidence of beriberi, and performed erythrocyte transketolase (ETK) assays. 13.4 % of infants had basal ETK<0.59 micromoles/min/gHb suggesting biochemical thiamin deficiency. Mortality was 5.5% but, among infants ≥2 months old, mortality was higher in those with basal ETK<0.59 micromoles/min/gHb (3/47, 6.4%) than in those with basal ETK≥0.59 micromoles/min/gHb (1/146, 0.7%) (P = 0.045, relative risk = 9.32 (95%CI 0.99 to 87.5)). We conclude that clinically unapparent thiamin deficiency is common among sick infants (≥2 months old) admitted to hospital in Vientiane. This may contribute to mortality and a low clinical threshold for providing thiamin to sick infants may be needed

    Erythrocyte Transketolase Activity, Markers of Cardiac Dysfunction and the Diagnosis of Infantile Beriberi

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    Infantile beriberi, or clinical thiamin (vitamin B1) deficiency in infants, is a forgotten disease in Asia, where ∼100 years ago it was a major public health problem. Children aged ∼2–3 months present in cardiac failure but usually rapidly improve if given thiamin injections. It remains relatively common in Vientiane, Lao PDR (Laos) probably because of prolonged intra- and post-partum maternal food avoidance behaviours. There has been very little recent research on the best diagnostic techniques. We conducted a case control study of 47 infants with beriberi and age-matched afebrile and febrile controls in Vientiane. The conventional measures of thiamin deficiency, basal and activated erythrocyte transketolase activities (ETK) and activation (α) coefficients, were assayed along with three markers of cardiac dysfunction - plasma brain natriuretic peptide, N-terminal pro-brain natriuretic peptide, and troponin T. Basal ETK was a better biochemical marker of infantile beriberi than the activation coefficient. Raised plasma troponin T may be a useful indicator of infantile beriberi in babies at risk and in the absence of other evident causes

    Inhibition of the MET Receptor Tyrosine Kinase as a Novel Therapeutic Strategy in Medulloblastoma123

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    Medulloblastoma is the most common pediatric posterior fossa malignancy, with a 5-year overall survival of only 60% and many survivors experiencing treatment-related morbidity secondary to current therapeutic regimens. With an improved understanding of the molecular basis for this disease, the opportunity to develop novel treatments with more tolerable toxicity profiles that target key molecular pathways, now exists. Recently, the hepatocyte growth factor (HGF)/MET signaling pathway has been implicated in medulloblastoma pathogenesis. Several therapeutic strategies targeting this pathway exist, including small molecule inhibitor therapy against the MET receptor tyrosine kinase. We examined the in vitro efficacy of targeting the MET receptor using the highly specific small molecule inhibitor PHA665752 as a novel treatment strategy in medulloblastoma. MET inhibition using PHA665752 was effective at reducing the proliferative capacity of the D283, ONS76, and MED8A medulloblastoma cell lines as assessed by MTS assay. Furthermore, PHA665752 treatment reduced D283 and ONS76 cell motility and impaired the growth of D283 cells in soft agar. Pretreatment of D283, ONS76, and MED8A cells with PHA665752 blocked exogenous recombinant human HGF-induced up-regulation of the downstream RAS/mitogen-activated protein kinase signaling pathway in D283, ONS76 and MED8A cell lines. Similarly, PHA665752 prevented HGF-induced phosphatidylinositol 3-kinase/AKT signaling in ONS76 and MED8A cells. These results highlight the efficacy of targeting the MET receptor tyrosine kinase therapeutically in medulloblastoma and provide support for further preclinical testing of small molecule inhibitors targeting the MET receptor in medulloblastoma

    The relationship of study and authorship characteristics on trial sponsorship and self-reported conflicts of interest among neuro-oncology clinical trials

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    Propose: To examine the association between trial sponsorship sources, self-reported conflicts of interest (COI), and study and author characteristics in central nervous system (CNS) oncology clinical trials (CT). Methods: MEDLINE search was performed for original CT on “Central Nervous System Neoplasms“[Mesh]. The investigators assessed for relationships between funding source (industry, academic or cooperative, none, not described), COI (presented, none, or not reported), CT, and author characteristics. Results: From 2010 to 2015, 319 CT were considered eligible. The majority of the studies involved primary gliomas (55.2%) and were Phase II CT (59.2%). Drug therapy was investigated in 83.0% of the CT. The remaining studies investigated surgery or radiotherapy. A minority of papers were published in journals with impact factor (IF) higher than > 10 (16%) or in regions other than North America and Europe (20.4%). Overall, 83.1% of studies disclosed funding sources: 32.6% from industry alone, 33.9% from an academic or cooperative group, and 10.7% from a mixed funding model. COI data was reported by 85.9% of trials, of which 56.2% reported no COI and 43.8% reported a related COI. Significant predictors for sponsorship (industry and/or academia) on univariate analysis were study design, type of intervention, journal impact factor, study conclusion, transparency of COI and presence of COI. On multivariate analysis, type of intervention, (P < 0.001), journal impact factor (IF) (P = 0.003), presence of COI (P < 0.001) and study conclusion (P = 0.003) remained significant predictors of sponsorship. For predicting COI, significant variables on univariate analysis were disease type, type of intervention, journal IF, funding source, and intervention arm being related to sponsor. On multivariate analysis, disease type (P = 0.003), journal IF (P < 0.001), type of intervention (P = 0.001), and funding source (P = 0.008) remained significant. Conclusions: The majority of CNS CT reported some external funding sources and non-related COI. We identified that drug trials, higher IF, presence of COI, and a neutral or negative study conclusion are associated with external funding. Likewise drug trials, higher IF, and glioma trials are associated with presence of COI

    Genetic and Epigenetic Inactivation of Kruppel-like Factor 4 in Medulloblastoma1

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    Although medulloblastoma is the most common pediatric malignant brain tumor, its molecular underpinnings are largely unknown. We have identified rare, recurrent homozygous deletions of Kruppel-like Factor 4 (KLF4) in medulloblastoma using high-resolution single nucleotide polymorphism arrays, digital karyotyping, and genomic real-time polymerase chain reaction (PCR). Furthermore, we show that there is loss of physiological KLF4 expression in more than 40% of primary medulloblastomas both at the RNA and protein levels. Medulloblastoma cell lines drastically increase the expression of KLF4 in response to the demethylating agent 5-azacytidine and demonstrate dense methylation of the promoter CpG island by bisulfite sequencing. Methylation-specific PCR targeting the KLF4 promoter demonstrates CpG methylation in approximately 16% of primary medulloblastomas. Reexpression of KLF4 in the D283 medulloblastoma cell line results in significant growth suppression both in vitro and in vivo. We conclude that KLF4 is inactivated by either genetic or epigenetic mechanisms in a large subset of medulloblastomas and that it likely functions as a tumor suppressor gene in the pathogenesis of medulloblastoma

    A Network-Based Approach to Glioma Surgery: Insights from Functional Neurosurgery

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    The evaluation and manipulation of structural and functional networks, which has been integral to advancing functional neurosurgery, is beginning to transcend classical subspecialty boundaries. Notably, its application in neuro-oncologic surgery has stimulated an exciting paradigm shift from the traditional localizationist approach, which is lacking in nuance and optimization. This manuscript reviews the existing literature and explores how structural and functional connectivity analyses have been leveraged to revolutionize and individualize pre-operative tumor evaluation and surgical planning. We describe how this novel approach may improve cognitive and neurologic preservation after surgery and attenuate tumor spread. Furthermore, we demonstrate how connectivity analysis combined with neuromodulation techniques can be employed to induce post-operative neuroplasticity and personalize neurorehabilitation. While the landscape of functional neuro-oncology is still evolving and requires further study to encourage more widespread adoption, this functional approach can transform the practice of neuro-oncologic surgery and improve the care and outcomes of patients with intra-axial tumors
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