Symptomatic Hyponatremia after Bowel Preparation: Report of Two Cases and Literature Review

INTRODUCTION: Bowel preparation for colonoscopy and/or colorectal surgery can cause electrolyte imbalances. The risk of electrolyte imbalances seems to be related to the type of bowel cleansing solution, age of patients and comorbidities. CASE REPORT: We report two cases of symptomatic hyponatremia (focal neurological signs and coma) after bowel preparation with sodium picosulfate/magnesium citrate for colonoscopy. In both cases, symptoms related to hyponatremia rapidly disappeared after sodium level correction with intravenous administration of hypertonic saline (3% NaCl). DISCUSSION: Electrolyte imbalances are more common with sodium phosphate-based solutions (NaP) and sodium picosulfate/magnesium citrate, in patients older than 65, in patients treated with thiazide diuretics, angiotensin-converting-enzyme inhibitor, betablockers or antidepressants and in gastrectomized patients. These patients should use macrogol-based solutions (polyethylene glycol). CONCLUSION: In patients at risk (patient > 65 years old, patients taking thiazide diuretics, angiotensin-converting-enzyme inhibitors, beta-blockers and antidepressants and with previous gastrectomy) we recommend macrogol-based solutionsinfo:eu-repo/semantics/publishedVersio

Synchronous intraductal papillary mucinous neoplasm and a pancreatic neuroendocrine tumor: more than a coincidence?

BACKGROUND: Although the association between intraductal papillary mucinous neoplasm of the pancreas (IPMN) and pancreatic neuroendocrine tumor (PNET) has been increasingly reported, whether this association is real or coincidence remains unclear. We report a case of synchronous IPMN and a PNET which were diagnosed preoperatively and discuss the tumorigenesis, clinicopathological features and management of these rare tumors based on the published literature. CASE REPORT: A 56-year-old male was incidentally diagnosed with a 14 mm branch duct IPMN and a 3.6 mm non-functional PNET during an evaluation due to persistent upper abdominal pain via endoscopic ultrasound. Close follow-up of the patient was decided as the IPMN had no worrisome features. A review of twenty-two previously reported cases of synchronous IPMN and PNET indicated that: a) only seven cases were diagnosed preoperatively; b) abdominal pain was the main presenting symptom; c) IPMN was the dominant tumor and presented with low grade dysplasia; d) the PNET was small and non-functional and had an indolent behavior; and e) only one case underwent radiologic follow-up. DISCUSSION: IPMN are associated with other pancreatic and extrapancreatic malignancies. Thus, the entire pancreatic parenchyma should be examined closely during the evaluation of an IPMN in order to exclude other pancreatic lesions, for example, a PNET.info:eu-repo/semantics/publishedVersio

Sequential Extensions of Causal and Evidential Decision Theory

Moving beyond the dualistic view in AI where agent and environment are separated incurs new challenges for decision making, as calculation of expected utility is no longer straightforward. The non-dualistic decision theory literature is split between causal decision theory and evidential decision theory. We extend these decision algorithms to the sequential setting where the agent alternates between taking actions and observing their consequences. We find that evidential decision theory has two natural extensions while causal decision theory only has one.Comment: ADT 201

mTOR pathway overactivation in BRAF mutated papillary thyroid carcinoma

CONTEXT: There are several genetic and molecular evidences suggesting dysregulation of the mammalian target of rapamycin (mTOR) pathway in thyroid neoplasia. Activation of the phosphatidylinositol-3-kinase/AKT pathway by RET/PTC and mutant RAS has already been demonstrated, but no data have been reported for the BRAF(V600E) mutation. OBJECTIVE: The aim of this study was to evaluate the activation pattern of the mTOR pathway in malignant thyroid lesions and whether it may be correlated with known genetic alterations, as well as to explore the mechanisms underlying mTOR pathway activation in these neoplasias. RESULTS: We observed, by immunohistochemical evaluation, an up-regulation/activation of the mTOR pathway proteins in thyroid cancer, particularly in conventional papillary thyroid carcinoma (cPTC). Overactivation of the mTOR signaling was particularly evident in cPTC samples harboring the BRAF(V600E) mutation. Transfection assays with BRAF expression vectors as well as BRAF knockdown by small interfering RNA revealed a positive association between BRAF expression and mTOR pathway activation, which appears to be mediated by pLKB1 Ser428, and emerged as a possible mechanism contributing to the association between BRAF mutation and mTOR pathway up-regulation. When we evaluated the rapamycin in the growth of thyroid cancer cell lines, we detected that cell lines with activating mutations in the MAPK pathway show a higher sensitivity to this drug. CONCLUSIONS: We determined that the AKT/mTOR pathway is particularly overactivated in human cPTC harboring the BRAF(V600E) mutation. Moreover, our results suggest that the mTOR pathway could be a good target to enhance therapy effects in certain types of thyroid carcinoma, namely in those harboring the BRAF(V600E) mutation

Mitochondrial dynamics and quality control in Huntington's disease

Huntington's disease (HD) is an inherited neurodegenerative disorder caused by polyglutamine expansion mutations in the huntingtin protein. Despite its ubiquitous distribution, expression of mutant huntingtin (mHtt) is particularly detrimental to medium spiny neurons within the striatum. Mitochondrial dysfunction has been associated with HD pathogenesis. Here we review the current evidence for mHtt-induced abnormalities in mitochondrial dynamics and quality control, with a particular focus on brain and neuronal data pertaining to striatal vulnerability. We address mHtt effects on mitochondrial biogenesis, protein import, complex assembly, fission and fusion, mitochondrial transport, and on the degradation of damaged mitochondria via autophagy (mitophagy). For an integrated perspective on potentially converging pathogenic mechanisms, we also address impaired autophagosomal transport and abnormal mHtt proteostasis in HD

Diffusion-weighted MR imaging findings in an isolated abscess of the clivus

We report the finding of restricted diffusion in an isolated abscess of the clivus and discuss the imaging differential diagnosis, with an emphasis on the usefulness of diffusion-weighted imaging

Giant cell glioblastoma: review of the literature and illustrated case

Giant cell glioblastoma is an infrequent variety of glioblastoma (5% of the cases). It has deserved a separate category in the World Health Organization classification of grade IV tumors. The clinical, imaging, histological and immunohistochemical characteristics, and the genetic alterations are reviewed. Treatment and prognosis are discussed and updated. The case of a patient that survived 19 months and died of spinal leptomeningeal metastases is illustrated

The role of c-Met and VEGFR2 in glioblastoma resistance to bevacizumab

Dismal prognosis of glioblastoma (GBM) prompts for the identification of response predictors and therapeutic resistance mechanisms of current therapies. The authors investigated the impact of c-Met, HGF, VEGFR2 expression and microvessel density (MVD) in GBM patients submitted to second-line chemotherapy with bevacizumab. Immunohistochemical expression of c-Met, HGF, VEGFR2, and MVD was assessed in tumor specimens of GBM patients treated with bevacizumab, after progression under temozolomide. Survival analysis was evaluated according to the expression of the aforementioned biomarkers. c-Met overexpression was associated with a time-to-progression (TTP) after bevacizumab of 3 months (95% CI, 1.5–4.5) compared with a TTP of 7 months (95% CI, 4.6–9.4) in patients with low or no expression of c-Met (p = 0.05). VEGFR2 expression was associated with a TTP after bevacizumab of 3 months (95% CI, 1.8–4.2) compared with a TTP of 7 months (95% CI, 5.7–8.3) in patients with no tumoral expression of VEGFR2 (p = 0.009). Concomitant c-Met/VEGFR2 overexpression was associated with worse overall survival (13 months) compared with concomitant c-Met/VEGFR2 negative expression (19 months; p = 0.025). Our data support the hypothesis that c-Met and VEGFR2 overexpression have a role in the development of glioblastoma early resistance and might predict poorer responses to anti-angiogenic therapies.This work was financed by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT-Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Inovação in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274). Additional funding by the European Regional Development Fund (ERDF), COMPETE2020 and Portuguese national funds via FCT, under project POCI-01-0145-FEDER-016390: CANCEL STEM and the project POCI-01-0145-FEDER-031438 (PDTC/MED_ONC/31438/2017)

TERTp mutations and p53 expression in head and neck cutaneous basal cell carcinomas with different aggressive features

Cutaneous basal cell carcinoma (cBCC) is an economic burden to health services, due to its great morbidity and increasing incidence in old people. Infiltrative cBCCs and cBCCs with micronodular pattern are considered as more aggressive. The role of p53 expression and TERTp mutation on cBCC behavior remains to be clarified. We aimed to assess TERTp mutations and p53 expression in relation to the cBCC histological subtype in a cohort of patients referred to an ENT Department of a tertiary Hospital of Northern Portugal. We performed a retrospective clinicopathological and histological review of the head and neck cBCCs followed-up at the otorhinolaryngology department of Trás-os-Montes e Alto Douro hospital (January 2007–June 2018). We assessed TERTp mutations in 142 cBCCs and p53 protein expression, through immunohistochemistry, in 157 cBCCs. We detected TERTp mutations in 43.7% of cBCCs and p53 overexpression in 60.5% of cBCCs. We spotted association of p53 overexpression and TERTp mutation with necrosis. In the infitrative-growth pattern cBCCs, there was no significant association with the clinical and histological features evaluated, except for necrosis. In the indolent-growth cBCCs, we identified a significant association of TERTp mutation status with female sex, necrosis, multiple cBCCs, and p53 positive expression. Our results suggest that TERTp mutation may be useful to identify more aggressive features in the indolent-growth pattern cBCCs (nodular and superficial subtypes). Further studies with larger cohorts are warranted to clarify the relevance of TERTp mutation in cBCCs.This study was supported by FCT, the Portuguese Foundation for Science and Technology through a Ph.D. Grant to SM (SFRH/BD/137802/2018). This work was financed by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT-Fundação para a Ciência e a Tecnolo-gia/Ministério da Ciência, Tecnologia e Inovação in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274). Additional funding by the European Regional Development Fund (ERDF) through the Operational Programme for Competitiveness and Internationalization—COMPETE2020, and Portuguese national funds via FCT, under project POCI-01-0145-FEDER-016390: CANCEL STEM and from the FCT, under the project POCI-01-0145-FEDER-031438: The other faces of telomerase: Looking beyond tumour immortalization (PDTC/MED-ONC/31438/2017)

Telomere erosion in memory T cells induced by telomerase inhibition at the site of antigenic challenge in vivo

This work was funded by grants from the Biotechnology and Biological Sciences Research Council Experimental Research on Aging Initiative, Research Into Aging, The Sir Jules Thorne Research Trust, and The Hayward Foundation and Dermatrust