966 research outputs found

    Free Mg(2+ )concentration in the calf muscle of glycogen phosphorylase and phosphofructokinase deficiency patients assessed in different metabolic conditions by (31)P MRS

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    BACKGROUND: The increase in cytosolic free Mg(2+ )occurring during exercise and initial recovery in human skeletal muscle is matched by a decrease in cytosolic pH as shown by in vivo phosphorus magnetic resonance spectroscopy ((31)P MRS). To investigate in vivo to what extent the homeostasis of intracellular free Mg(2+ )is linked to pH in human skeletal muscle, we studied patients with metabolic myopathies due to different disorders of glycogen metabolism that share a lack of intracellular acidification during muscle exercise. METHODS: We assessed by (31)P MRS the cytosolic pH and free magnesium concentration ([Mg(2+)]) in calf muscle during exercise and post-exercise recovery in two patients with McArdle's disease with muscle glycogen phosphorylase deficiency (McArdle), and two brothers both affected by Tarui's disease with muscle phosphofructokinase deficiency (PFK). RESULTS: All patients displayed a lack of intracellular acidosis during muscle exercise. At rest only one PFK patient showed a [Mg(2+)] higher than the value found in control subjects. During exercise and recovery the McArdle patients did not show any significant change in free [Mg(2+)], while both PFK patients showed decreased free [Mg(2+)] and a remarkable accumulation of phosphomonoesters (PME). During initial recovery both McArdle patients showed a small increase in free [Mg(2+)] while in PFK patients the pattern of free [Mg(2+)] was related to the rate of PME recovery. CONCLUSION: i) homeostasis of free [Mg(2+)] in human skeletal muscle is strongly linked to pH as shown by patients' [Mg(2+)] pattern during exercise; ii) the pattern of [Mg(2+)] during exercise and post-exercise recovery in both PFK patients suggests that [Mg(2+)] is influenced by the accumulation of the phosphorylated monosaccharide intermediates of glycogenolysis, as shown by the increased PME peak signal. iii) (31)P MRS is a suitable tool for the in vivo assessment of free cytosolic [Mg(2+)] in human skeletal muscle in different metabolic conditions

    Epigenomic and somatic mutations of pituitary tumors with clinical and pathological correlations in 111 patients

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    Objective To profile clinically non-aggressive and aggressive pituitary adenomas (PAs)/pituitary neuroendocrine tumours (PitNETs) and pituitary carcinomas for somatic mutations and epigenetic alterations of genes involved in cell proliferation/differentiation, microRNAs (miRNA)/long noncoding RNA (LncRNA)-post-transcriptional regulators and therapy targets. Design Retrospective observational study. Patients and Measurements A total of 64 non-aggressive and 41 aggressive PAs/PitNETs and 6 pituitary carcinomas treated by endoscopic surgery with >= 1-year follow-up were included. Somatic mutations of 17 genes and DNA methylation of 22 genes were assessed. Ten normal pituitaries were used as control. Results We found at least one mutation in 17 tumours, including 6/64 non-aggressive, 10/41 aggressive PAs/PitNETs, and 1/6 pituitary carcinoma. AIP (N = 6) was the most frequently mutated gene, followed by NOTCH (4), and TP53 (3). Hypermethylation of PARP15, LINC00599, ZAP70 was more common in aggressive than non-aggressive PAs/PITNETs (p < .05). Lower levels of methylation of AIP, GNAS and PDCD1 were detected in aggressive PAs/PITNETs than non-aggressive ones (p < .05). For X-linked genes, males presented higher level of methylation of FLNA, UXT and MAGE family (MAGEA11, MAGEA1, MAGEC2) genes in aggressive vs. non-aggressive PAs/PITNETs (p < .05). In pituitary carcinomas, methylation of autosomal genes PARP15, LINC00599, MIR193 and ZAP70 was higher than in PAs/PITNETs, while X-linked genes methylation level was lower. Conclusions Somatic mutations and methylation levels of genes involved in cell proliferation/differentiation, miRNA/LncRNA-post-transcriptional regulators and targets of antineoplastic therapies are different in non-aggressive and in aggressive PAs/PitNETs. Methylation profile also varies according to gender. Combined genetic-epigenetic analysis, in association with clinico-radiological-pathological data, may be of help in predicting PA/PitNET behaviour

    Current State-of-the-Art of AI Methods Applied to MRI

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    Di Noia, C., Grist, J. T., Riemer, F., Lyasheva, M., Fabozzi, M., Castelli, M., Lodi, R., Tonon, C., Rundo, L., & Zaccagna, F. (2022). Predicting Survival in Patients with Brain Tumors: Current State-of-the-Art of AI Methods Applied to MRI. Diagnostics, 12(9), 1-16. [2125]. https://doi.org/10.3390/diagnostics12092125Given growing clinical needs, in recent years Artificial Intelligence (AI) techniques have increasingly been used to define the best approaches for survival assessment and prediction in patients with brain tumors. Advances in computational resources, and the collection of (mainly) public databases, have promoted this rapid development. This narrative review of the current state-of-the-art aimed to survey current applications of AI in predicting survival in patients with brain tumors, with a focus on Magnetic Resonance Imaging (MRI). An extensive search was performed on PubMed and Google Scholar using a Boolean research query based on MeSH terms and restricting the search to the period between 2012 and 2022. Fifty studies were selected, mainly based on Machine Learning (ML), Deep Learning (DL), radiomics-based methods, and methods that exploit traditional imaging techniques for survival assessment. In addition, we focused on two distinct tasks related to survival assessment: the first on the classification of subjects into survival classes (short and long-term or eventually short, mid and long-term) to stratify patients in distinct groups. The second focused on quantification, in days or months, of the individual survival interval. Our survey showed excellent state-of-the-art methods for the first, with accuracy up to ∼98%. The latter task appears to be the most challenging, but state-of-the-art techniques showed promising results, albeit with limitations, with C-Index up to ∼0.91. In conclusion, according to the specific task, the available computational methods perform differently, and the choice of the best one to use is non-univocal and dependent on many aspects. Unequivocally, the use of features derived from quantitative imaging has been shown to be advantageous for AI applications, including survival prediction. This evidence from the literature motivates further research in the field of AI-powered methods for survival prediction in patients with brain tumors, in particular, using the wealth of information provided by quantitative MRI techniques.publishersversionpublishe

    Distinct MRI pattern of "pseudoresponse" in recurrent glioblastoma multiforme treated with regorafenib: Case report and literature review

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    : Antiangiogenic agents can induce a distinct MRI pattern in glioblastoma, characterized by a decrease in the contrast enhancement on T1-weighted images and a simultaneous hyperintensity on T2-weighted or fluid-attenuated inversion recovery images

    Open-aqueduct LOVA, LIAS, iNPH: a comparative clinical-radiological study exploring the "grey zone" between different forms of chronic adulthood hydrocephalus

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    The definition of chronic adult hydrocephalus encompasses different pathological entities with overlapping characteristics, including long-standing overt ventriculomegaly in adults (LOVA), late-onset idiopathic aqueductal stenosis (LIAS) and idiopathic normal pressure hydrocephalus (iNPH). The aim of our study was to identify preoperative clinical and radiological features peculiar of these diseases providing some pathophysiology inferences on these forms of hydrocephalus

    Endoscopic endonasal approach for loco-regional recurrent clivus chordomas

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    Introduction. Role of surgery for loco-regional recurrences of clivus chordomas (CCs) is still debated. It has been proposed in selected cases with a curative or with palliative intent, eventually followed by radiation or chemo/radiation treatments. Only limited data on the endoscopic endonasal approach (EEA) are available. Research question. To assess the role of EEA for loco-regional recurrent CCs. Materials and Methods. All consecutive loco-regional recurrent CCs operated by EEA at our Institution from 1998 to 2021 were identified. The extension of tumor resection, symptoms control, overall survival (OS), and progression free survival (PFS) were assessed. Results. Series includes 54 patients (53.7% females, mean age 55± 14 years). Surgery was planned with a resective aim in 35 (64.8%) patients, while it was palliative in 19 (35.2%). Gross tumor removal was achieved in 24 cases (44.4%). Main complications consisted of 2 (3.7%) CSF leaks. Further local relapses were observed in 30 (55.5%) patients after 25± 24 months; 29 (53.7%) patients deceased after 34 ± 31 months. OS and PFS were lower in these cases than primary surgeries (p<0.001 and p<0.001), but cases undergone surgery with a resective aim had a significant better OS and PFS than for those treated for palliation (p<0.001). Determinants of recurrences were tumoral size (p=0.48) and previous radiotherapy (p=009). Discussion and Conclusions. EEA has proven to be effective for loco-regional recurrent CCs alleviating patients symptoms and preserving their quality of life with limited morbidities. However, because overall prognosis is poor, EEA should be reserved to selected recurrent cases

    Triple combination of lomustine, temozolomide and irradiation reduces canine glioma cell survival in vitro

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    Background: Combined chemoradiation offers a promising therapeutic strategy for dogs with glioma. The alkylating agents temozolomide (TMZ) and lomustine (CCNU) penetrate the blood-brain barrier, and doses for dogs are established. Whether such combinations are clinically advantageous remains to be explored together with tumour-specific markers. Objective: To investigate if triple combination of lomustine, temozolomide and irradiation reduces canine glioma cell survival in vitro. Methods: We evaluated the sensitising effect of CCNU alone and in combination with TMZ-irradiation in canine glioma J3T-BG cells and long-term drug-exposed subclones by using clonogenic survival and proliferation assays. Bisulphite-SEQ and Western Blot were used to investigate molecular alterations. Results: TMZ (200 μM) or CCNU alone (5 μM) reduced the irradiated survival fraction (4 Gy) from 60% to 38% (p = 0.0074) and 26% (p = 0.0002), respectively. The double-drug combination reduced the irradiated survival fraction (4 Gy) more potently to 12% (p < 0.0001). After long-term drug exposure, both subclones show higher IC50 values against CCNU and TMZ. For CCNU-resistant cells, both, single-drug CCNU (p = 0.0006) and TMZ (p = 0.0326) treatment combined with irradiation (4 Gy) remained effective. The double-drug-irradiation combination reduced the cell survival by 86% (p < 0.0001), compared to 92% in the parental (nonresistant) cell line. For TMZ-resistant cells, only the double-drug combination with irradiation (4 Gy) reduced the cell survival by 88% (p = 0.0057) while single-drug treatment lost efficacy. Chemoresistant cell lines demonstrated higher P-gp expression while MGMT-methylation profile analysis showed a general high methylation level in the parental and long-term treated cell lines. Conclusions: Our findings indicate that combining CCNU with TMZ-irradiation significantly reduces canine glioma cell survival. Such a combination could overcome current challenges of therapeutic resistance to improve overall patient survival
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