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Background The COVID-19 pandemic transformed the health care systems, motivating Telemedicine's rapid evolution and implementation. Telemedicine (TM) can potentially improve the quality of primary health care and increase accessibility to the population. Nevertheless, its use may represent a challenge to older people as they may have different needs from the general population due to potential age-related changes in perceptual, motor and cognitive capacities. We thus aimed to identify potential facilitators and barriers to Telemedicine (TM) use in the primary care of older adults and develop recommendations. Methods We conducted a multi-phase study: 1. A systematic mixed-method review to explore determinants in the use of TM for older adults for papers published before July 2021; 2. Qualitative descriptive study, we interviewed 29 older adults and conducted three focus groups and one deliberative dialogue with healthcare professionals from four McGill family medicine sites. The findings were analyzed using deductive thematic analysis based on the Consolidated Framework for Implementation Research (CFIR); 3. We integrated the results from both phases and the deliberative dialogue using thematic analysis. Results The systematic review identified over 3,328 references. We included 21 articles, resulting in positive experiences and high satisfaction and generating interest in TM as a complementary healthcare delivery model. Participants agreed that TM contributed to maintaining the continuity of care and was convenient when there is a previous/established patient-physician relationship and to resolve minor health issues. TM was beneficial for persons with limited mobility; and reduced the exposure of older adults to potential high-risk environments. Nevertheless, participants expressed concerns about the lack of visual contact, causing essential details to be overlooked. Similarly, miscommunication difficulties may emerge due to language or hearing barriers. Family physicians perceived that most patients did not consider phone consultations a medical act. However, participants were amenable to a hybrid approach, combining in-person consultations and Telemedicine, depending on their health conditions. Conclusions Older adults and healthcare professionals consider Telemedicine a good alternative for accessing healthcare services, though it would be necessary to promote a hybrid approach and encourage and support familiarization, adaptability, and accessibility to technological tools.

Programming is fast becoming a required skill set for students in every country. We present CS Bridge, a model for cross-border co-teaching of CS1, along with a corresponding open-source course-in-a-box curriculum made for easy localization. In the CS Bridge model, instructors and student-teachers from different countries come together to teach a short, stand-alone CS1 course to hundreds of local high school students. The corresponding open-source curriculum has been specifically designed to be easily adapted to a wide variety of local teaching practices, languages, and cultures. Over the past six years, the curriculum has been used to teach CS1 material to over 1,000 high school students in Colombia, the Czech Republic, Turkey, and Guinea. A large majority of our students continue on to study CS or CS-related fields in university. More importantly, many of our undergraduate student-teachers stay involved with teaching beyond the program. Joint teaching creates a positive, high-quality learning experience for students around the world and a powerful, high-impact professional development experience for the teaching team---instructors and student-teachers alike.

Striatal-enriched protein tyrosine phosphatase (STEP) modulates key signaling molecules involved in synaptic plasticity and neuronal function. It is postulated that STEP opposes the development of long-term potentiation (LTP) and that it exerts a restraint on long-term memory (LTM). Here, we examined whether STEP61 levels are regulated during hippocampal LTP and after training in hippocampal-dependent tasks. We found that after inducing LTP by high frequency stimulation or theta-burst stimulation STEP61 levels were significantly reduced, with a concomitant increase of STEP33 levels, a product of calpain cleavage. Importantly, inhibition of STEP with TC-2153 improved LTP in hippocampal slices. Moreover, we observed that after training in the passive avoidance and the T-maze spontaneous alternation task, hippocampal STEP61 levels were significantly reduced, but STEP33 levels were unchanged. Yet, hippocampal BDNF content and TrkB levels were increased in trained mice, and it is known that BDNF promotes STEP degradation through the proteasome. Accordingly, hippocampal pTrkBTyr816, pPLCγTyr783, and protein ubiquitination levels were increased in T-SAT trained mice. Remarkably, injection of the TrkB antagonist ANA-12 (2 mg/Kg, but not 0.5 mg/Kg) elicited LTM deficits and promoted STEP61 accumulation in the hippocampus. Also, STEP knockout mice outperformed wild-type animals in an age- and test-dependent manner. Summarizing, STEP61 undergoes proteolytic degradation in conditions leading to synaptic strengthening and memory formation, thus highlighting its role as a molecular constrain, which is removed to enable the activation of pathways important for plasticity processes., This work was supported by the Ministerio de Economia y Competitividad, Spain (SAF2016-08573-R to E. PérezNavarro and BFU2014-57929-P, cofinanced by FEDER, to E.D. Martín).

Introduction: Huntington’s disease (HD), an autosomal dominant neurodegenerative disorder caused by an expansion of CAG repeats in the huntingtin gene, has long been characterized by the presence of motor symptoms due to the loss of striatal projection neurons. Cognitive dysfunction and neuropsychiatric symptoms are also present and they occur in the absence of cell death in most mouse models, pointing to neuronal dysfunction and abnormal synaptic plasticity as causative mechanisms.Areas covered: Here, we focus on those common mechanisms altered by the presence of mutant huntingtin affecting corticostriatal and hippocampal function as therapeutic targets that could prove beneficial to ameliorate both cognitive and motor function in HD. Specifically, we discuss the importance of reestablishing the balance in (1) synaptic/extrasynaptic N-methyl-D-aspartate receptor signaling, (2) mitochondrial dynamics/trafficking, (3) TrkB/p75NTR signaling, and (4) transcriptional activity.Expert opinion: Mutant hu...

Background Chelerythrine is widely used as a broad range protein kinase C (PKC) inhibitor, but there is controversy about its inhibitory effect. Moreover, it has been shown to exert PKC-independent effects on non-neuronal cells. Methods In this study we investigated possible off-target effects of chelerythrine on cultured cortical rodent neurons and a neuronal cell line. Results We found that 10 μM chelerythrine, a commonly used concentration in neuronal cultures, reduces PKC and cAMP-dependent protein kinase substrates phosphorylation in mouse cultured cortical neurons, but not in rat primary cortical neurons or in a striatal cell line. Furthermore, we found that incubation with chelerythrine increases pERK1/2 levels in all models studied. Moreover, our results show that chelerythrine promotes calpain activation as assessed by the cleavage of spectrin, striatal-enriched protein tyrosine phosphatase and calcineurin A. Remarkably, chelerythrine induces a concentration-dependent increase in intracellular Ca2+ levels that mediates calpain activation. In addition, we found that chelerythrine induces ERK1/2- and calpain-independent caspase-3 activation that can be prevented by the Ca2+ chelator BAPTA-AM. Conclusions This is the first report showing that chelerythrine promotes Ca2+-dependent calpain activation in neuronal cells, which has consequences for the interpretation of studies using this compound. General significance Chelerythrine is still marketed as a specific PKC inhibitor and extensively used in signal transduction studies. We believe that the described off-target effects should preclude its use as a PKC inhibitor in future works.

One of the main focuses in Huntington's disease (HD) research, as well as in most neurodegenerative diseases, is the development of new therapeutic strategies, as currently there is no treatment to delay or prevent the progression of the disease. Neuronal dysfunction and neuronal death in HD are caused by a combination of interrelated pathogenic processes that lead to motor, cognitive and psychiatric symptoms. Understanding how mutant huntingtin impacts on a plethora of cellular functions could help to identify new molecular targets. Although HD has been classically classified as a neurodegenerative disease affecting voluntary movement, lately cognitive dysfunction is receiving increased attention as it is very invalidating for patients. Thus, an ambitious goal in HD research is to find altered molecular mechanisms that contribute to cognitive decline. In this review, we have focused on those findings related to corticostriatal and hippocampal cognitive dysfunction in HD, as well as on the underlying molecular mechanisms, which constitute potential therapeutic targets. These include alterations in synaptic plasticity, transcriptional machinery and neurotrophic and neurotransmitter signaling.

In Colombia, oil and gas production contributes to a 4.4% of GDP as of 2016 and is considered a vital resource for the national economic development. Today, the oil and gas production is around 830.000 barrels per day. In the past 100 years, there are key geographical areas in the country where the oil and gas industry has been operating. Over the years, the oil and gas industry in Colombia has faced challenges with the communities behavior, environmental incidents and changes on the environment regulation. As a result of this, in the last three years Colombia has reported more than 9,000 barrels of oil per day (bpd) of deferred production, due to strikes that directly affect field operations. The following article describes the factors considered in Colombia for the successful adaptation and application of Energy4me, a Society of Petroleum Engineers energy education methodology that explains the oil and gas concepts through innovative laboratories that help understand, in a simple way, how the oil industry works. In the last two years, more than 8,000 people have been involved in the Energy4me program in Colombia. This paper describes the methodology applied for the successful execution of the Energy4me program; integrating the analysis of the targeted population, adaptation of the technical information and the industry's view on the environment. Additionally, it quantitatively portraits the participation of student volunteers from different universities around the country and the positive impact of this experience. Sample design techniques and data analysis are applied to quantitatively measure the results obtained, among which stands out the decrease of the energy industry rejection by at least 58%, as well as other benefits; which are backed up by the theory of shared value. With the novel adaptation and implementation of the pedagogical methodology of Energy4Me and with the creation of new educational materials to simplify technical knowledge sharing, it is concluded that a healthy communication channel between the energy sector and the communities exposed to oil operations can be constructed to achieve a reduction in the overall communities oil and gas rejection.

Background Obesity is associated with higher leukocyte counts, whereas weight loss decreases these counts. It is unknown if different bariatric surgery (BS) types have different effects on leukocytes. Objectives The aim of the study was to determine predictors of leukocyte and their subset count variation in patients submitted to BS. Setting Tertiary care university hospital, Porto, Portugal. Methods This was a retrospective analysis of patients submitted to Roux-en-Y gastric bypass (RYGB), laparoscopic adjustable gastric banding (LAGB), or sleeve gastrectomy (SG). Leukocyte and subset counts were compared between baseline and 1-year postsurgery and between BS types. A multivariate linear regression model was built to study determinants of leukocyte and subset variation. Results We analyzed 764 patients: 238 submitted to LAGB; 452 to RYGB, and 74 to SG. Mean age was 42 years and 86.6% were women. All BS types were associated with a decrease in leukocyte and neutrophil counts but the variation in body mass index and homeostatic model assessment (HOMA-IR) were the only variables independently associated with a decrease 1-year postsurgery. Monocytes increased in patients submitted to LAGB and decreased in those who underwent RYGB and SG. The BS type was independently associated with monocyte variation. Patients who underwent RYGB and SG had a decrease in monocyte counts of 77/µL and 62/µL, respectively, compared with LAGB. Conclusion Weight and insulin resistance are the main predictors of leukocyte and neutrophil variation after BS. The specific type of BS is a determinant of monocyte count variation independent of the amount of weight loss or the degree of insulin resistance improvement.

Caffeine has cognitive-enhancing properties with effects on learning and memory, concentration, arousal and mood. These effects imply changes at circuital and synaptic level, but the mechanism by which caffeine modifies synaptic plasticity remains elusive. Here we report that caffeine, at concentrations representing moderate to high levels of consumption in humans, induces an NMDA receptor-independent form of LTP (CAFLTP) in the CA1 region of the hippocampus by promoting calcium-dependent secretion of BDNF, which subsequently activates TrkB-mediated signaling required for the expression of CAFLTP. Our data include the novel observation that insulin receptor substrate 2 (IRS2) is phosphorylated during induction of CAFLTP, a process that requires cytosolic free Ca2+. Consistent with the involvement of IRS2 signals in caffeine-mediated synaptic plasticity, phosphorylation of Akt (Ser473) in response to LTP induction is defective in Irs2−/− mice, demonstrating that these plasticity changes are associated with downstream targets of the phosphoinositide 3-kinase (PI3K) pathway. These findings indicate that TrkB-IRS2 signals are essential for activation of PI3K during the induction of LTP by caffeine.

Bariatric surgery can improve glucose metabolism in obese patients with diabetes, but the factors that can predict diabetes remission are still under discussion. The present study aims to examine the impact of preoperative beta cell function on diabetes remission following surgery.We investigated a cohort of 363 obese diabetic patients who underwent bariatric surgery. The impact of several preoperative beta cell function indexes on diabetes remission was explored through bivariate logistic regression models.Postoperative diabetes remission was achieved in 39.9 % of patients. Younger patients (p 0.001) and those with lower HbA1c (p = 0.001) at the baseline evaluation had higher odds of diabetes remission. Use of oral anti-diabetics and insulin therapy did not reach statistical significance when they were adjusted for age and HbA1c. Among the evaluated indexes of beta cell function, higher values of insulinogenix index, Stumvoll first- and second-phase indexes, fasting C-peptide, C-peptide area under the curve (AUC), C-peptide/glucose AUC, ISR (insulin secretion rate) AUC, and ISR/glucose AUC predicted diabetes remission even after adjustment for age and HbA1c. Among them, C-peptide AUC had the higher discriminative power (AUC 0.76; p 0.001).Patients' age and preoperative HbA1c can forecast diabetes remission following surgery. Unlike other studies, our group found that the use of oral anti-diabetics and insulin therapy were not independent predictors of postoperative diabetes status. Preoperative beta cell function, mainly C-peptide AUC, is useful in predicting diabetes remission, and it should be assessed in all obese diabetic patients before bariatric or metabolic surgery.

ResumoIntroduçãoA osteoporose é a doença metabólica do osso mais frequente, afetando sobretudo mulheres pós‐menopausa e homens idosos.ObjetivoResponder a 12 questões referentes ao diagnóstico e tratamento da osteoporose.MétodosPesquisa bibliográfica na base de dados Medline. Revistas às referências bibliográficas dos artigos selecionados e pesquisadas para inclusão as de maior relevo.Conclusões1 ‐ O que é? Caracteriza‐se por diminuição da massa óssea e deterioração da microarquitectura, com aumento da fragilidade óssea e do risco de fraturas. 2 ‐ Qual é a clínica? Clinicamente silenciosa até à ocorrência de fraturas. 3 ‐ Quais os fatores de risco? O principal fator é uma densidade mineral óssea baixa (avaliada por absorciometria radiológica de energia dupla [DXA]), mas outros contribuem para o risco total de fratura. 4 ‐ Quais as causas secundárias? Doenças metabólicas, endocrinológicas, gastrointestinais, do tecido conjuntivo ou fármacos. São mais comuns em mulheres pré‐menopausa e homens. 5 ‐ Quem rastrear? Devem ser avaliados quanto à presença de fatores de risco todos os indivíduos com mais de 50 anos. 6 ‐ Como rastrear? Identificar fatores de risco clínicos que impliquem realização de DXA. 7 ‐ Com que periodicidade repetir DXA? Varia com o resultado do teste prévio e probabilidade de perda óssea. 8 ‐ Como avaliar? Avaliar todos os doentes clínica e laboratorialmente para excluir causas secundárias e selecionar o tratamento mais adequado. Alguns podem necessitar de exames específicos. 9 ‐ Quem tratar? O tratamento está indicado conforme o risco de fratura (calculado através da ferramenta FRAX®). 10 ‐ Como tratar? Estão indicadas medidas de prevenção primária, a iniciar na infância. Diversos fármacos têm demonstrado eficácia, sendo abordadas as indicações para cada um. 11 ‐ Quanto tempo tratar? Permanece incerta a duração ótima, sugerindo‐se o conceito de “drug holiday”. 12 ‐ Como monitorizar? Realizar DXA 1‐2 anos após o inicio do tratamento. Biomarcadores ósseos, apesar de promissores, ainda não estão recomendados.AbstractIntroductionOsteoporosis is the most common metabolic bone disease, affecting mainly postmenopausal women and older men.AimAnswer to 12 key questions regarding osteoporosis diagnosis and treatment.MethodsLiterature search in Medline database. References of the selected articles were revised and the most relevant articles were also included.Conclusions1 ‐ What is osteoporosis? It is characterized by low bone mass and deterioration of microarchitecture, with increased bone fragility and risk of fractures. 2 ‐ What are the clinical manifestations? It is clinically silent until fracture occurs. 3 ‐ What are the risk factors? The main factor is low bone mineral density (assessed by dual energy X‐ray absorptiometry ‐ DXA), but others contribute to the overall risk of fracture. 4 ‐ What are the secondary causes? Metabolic, endocrine, gastrointestinal, connective tissue diseases or drugs. They are more common in premenopausal women and men. 5 ‐ Who should be screened? All individuals over 50 years should be evaluated for the presence of clinical risk factors. 6 ‐ How to screen? By identification of risk factors that suggest performing DXA. 7 ‐ How frequently should DXA be repeated? It varies with the result of the previous test and the probability of bone loss. 8 ‐ How to evaluate osteoporotic patients? Evaluate all patients clinically and perform exams to exclude secondary causes and select the most appropriate pharmacological treatment. Some may require specific tests. 9 ‐ Who should be treated? The treatment is indicated according to the risk of fracture (calculated by FRAX® tool). 10 ‐ How to treat? Primary prevention measures are recommended since childhood. Several drugs have demonstrated efficacy, being addressed the indications to each of them. 11 ‐ How long to treat? The optimal duration remains uncertain, being suggested the concept of “drug holiday”. 12 ‐ How to monitor? Perform DXA 1 to 2 years after starting treatment. Bone biomarkers, although promising, are not recommended.

Striatal-enriched protein tyrosine phosphatase (STEP) modulates key signaling molecules involved in synaptic plasticity and neuronal function. It is postulated that STEP opposes the development of long-term potentiation (LTP) and that it exerts a restraint on long-term memory (LTM). Here, we examined whether STEP

Pituitary adenomas and paragangliomas/pheocromocytomas are rare endocrine tumours, which can be sporadic or familial. During many years their coexistence in the same individual was considered a coincidental finding. However, an association between these two entities was recently demonstrated, with the possible involvement of SDHx genes. We describe a 57-year-old female patient, who was under surveillance since 1997 for a malignant paraganglioma with vertebral bone metastasis, and harboured a germline frameshift mutation in exon 6 of SDHB gene [c.587–591DelC]. Seventeen years later, she was diagnosed with acromegaly and underwent transesphenoidal endoscopic resection of a somatotropinoma. Three months after surgery she started treatment with lanreotide for residual disease. Despite initial good response, she developed resistance to first generation of somatostatin analogues and treatment had to be switched to pegvisomant. In the immunohistochemical staining, the pituitary adenoma was positive for SDHA expression, while SDHB showed an heterogeneous staining pattern, with areas markedly positive and others with positive and negative cells. Our findings provide useful data for understanding the link between paragangliomas/pheocromocytomas and somatotropinomas. While we confirm the well-established link between SDHB mutations and paragangliomas/pheocromocytomas, particularly with malignant paragangliomas, the preservation—at least partially—of SDHB expression in the somatotropinoma tissue does not allow drawing definite conclusions about the involvement of the SDHB mutation in pituitary adenoma.

Bariatric surgery improves lipid profile. A still unanswered question is whether this improvement is merely weight-dependent or also results from factors inherent to specificities of the bariatric procedure. We aimed to study lipid profile 1 year after bariatric surgery and compare its changes between the different procedures in patients matched for initial weight and weight loss. We retrospectively analysed patients submitted to Roux-en-Y gastric bypass (RYGB), adjustable gastric banding (AGB) or sleeve gastrectomy (SG) between 2010 and 2013. Patients were matched for age (±5 years), sex, pre-surgery body mass index (BMI) (±2 Kg/m2) and excess weight loss (EWL) (±5 %). Baseline and 1-year lipid profile, its variation and percentage of variation was compared between surgeries. We analysed 229 patients: 72 pairs RYGB-AGB, 47 pairs RYGB-SG and 33 pairs AGB-SG. The median age was 41 (35–52) years and 11.8 % were male. Pre-operative BMI was 44.0 ± 4.6 and 32.1 ± 4.4 Kg/m2 at 1 year. EWL at 1 year was 64.2 ± 18.9 %. There were no differences in baseline lipid profile between patients submitted to different types of bariatric surgery. At 1 year, high-density lipoprotein cholesterol (HDL) and triglycerides (TG) improved similarly with all surgeries. Total cholesterol (TC) and low-density lipoprotein cholesterol (LDL) at 1 year decreased significantly more in patients submitted to RYGB than in weight-matched patients undergoing AGB or SG. RYGB is the only bariatric surgery that reduces TC and LDL in age-, sex-, BMI- and EWL-matched patients. All three procedures improved TG and HDL similarly when the confounding effect of weight loss is eliminated.

Permanent neonatal diabetes (PNDM) can result from activating heterozygous mutations in KCNJ11 gene, encoding the Kir6.2 subunit of the pancreatic ATP-sensitive potassium channels (KATP). Sulfonylureas promote KATP closure and stimulate insulin secretion, being an alternative therapy in PNDM, instead of insulin. Male, 20 years old, diagnosed with diabetes at 3 months of age. The genetic study identified a novel heterozygous mutation in exon 1 of the KCNJ11 gene – KCNJ11:c1001G>7 (p.Gly334Val) – and confirmed the diagnosis of PNDM. Therefore it was attempted to switch from insulin therapy to sulfonylurea. During glibenclamide institution C-peptide levels increased, however the suboptimal glycemic control lead us to restart an intensive insulin scheme. This new variant of KCNJ11 mutation had a phenotypic lack of response to sulfonylurea therapy. Age, prior poor metabolic control and functional change of KATP channel induced by this specific mutation may explain the observed unsuccessful switch to sulfonylurea. Interestingly, C-peptide levels raise during glibenclamide administration support some degree of improvement in insulin secretory capacity induced by the treatment. Understanding the response to sulfonylurea is crucial as successful treatment may be life-changing in these patients.

Recent results indicate that STriatal-Enriched protein tyrosine Phosphatase (STEP) levels are regulated by brain-derived neurotrophic factor (BDNF), whose expression changes during postnatal development and aging. Here, we studied STEP ontogeny in mouse brain and changes in STEP with age with emphasis on the possible regulation by BDNF. We found that STEP expression increased during the first weeks of life, reaching adult levels by 2-3 weeks of age in the striatum and cortex, and by postnatal day (P) 7 in the hippocampus. STEP protein levels were unaffected in BDNF+/- mice, but were significantly reduced in the striatum and cortex, but not in the hippocampus, of BDNF-/- mice at P7 and P14. In adult wild-type mice there were no changes in cortical and hippocampal STEP61 levels with age. Conversely, striatal STEP levels were reduced from 12 months of age, correlating with higher ubiquitination and increased BDNF content and signaling. Lower STEP levels in older mice were paralleled by increased phosphorylation of its substrates. Since altered STEP levels are involved in cellular malfunctioning events, its reduction in the striatum with increasing age should encourage future studies of how this imbalance might participate in the aging process.

Math education faces the challenge not only of how to teach math, but also of what math to teach. With the intention of promoting math's big ideas in formal and informal settings, we created DiMBI (Discovering Math's multimedia platform developed in Processing that uses reacTIVision to read users' interactions with selected tangible regular polygons (a triangle and a square). The corners of each polygon are linked with specific features that aim to promote transfer learning (colors and music). The features change as the user manipulates the objects through symmetric actions and permutation of corners. This is the first stage of our technology, which aims to bring big math ideas closer to the people, through more concrete interactions.

Huntington's disease (HD) causes motor disturbances, preceded by cognitive impairment, in patients and mouse models. We showed that increased hippocampal cAMP-dependent protein kinase (PKA) signaling disrupts recognition and spatial memories in R6 HD mouse models. However, unchanged levels of hippocampal phosphorylated (p) cAMP-responsive element-binding protein (CREB) suggested unaltered nuclear PKA activity in R6 mice. Here, we extend this finding by showing that nuclear pPKA catalytic subunit (Thr197) and pPKA substrate levels were unaltered in the hippocampus of R6/1 mice. Phosphodiesterases (PDEs) play an important role in the regulation of PKA activity. PDE10A, a cAMP/cGMP dual-substrate PDE, was reported to be restricted to the nuclear region in nonstriatal neurons. Using cell fractionation we confirmed that PDE10A was enriched in nuclear fractions, both in wild-type and R6/1 mice hippocampus, without differences in its levels or intracellular distribution between genotypes. We next investigated whether inhibition of PDE10 with papaverine could improve cognitive function in HD mice. Papaverine treatment improved spatial and object recognition memories in R6/1 mice, and significantly increased pGluA1 and pCREB levels in R6/1 mice hippocampus. Papaverine likely acted through the activation of the PKA pathway as the phosphorylation level of distinct cGMP-dependent kinase (cGK) substrates was not modified in either genotype. Moreover, hippocampal cAMP, but not cGMP, levels were increased after acute papaverine injection. Our results show that inhibition of PDE10 improves cognition in R6 mice, at least in part through increased GluA1 and CREB phosphorylation. Thus, PDE10 might be a good therapeutic target to improve cognitive impairment in HD.

Chelerythrine is widely used as a broad range protein kinase C (PKC) inhibitor, but there is controversy about its inhibitory effect. Moreover, it has been shown to exert PKC-independent effects on non-neuronal cells.In this study we investigated possible off-target effects of chelerythrine on cultured cortical rodent neurons and a neuronal cell line.We found that 10μM chelerythrine, a commonly used concentration in neuronal cultures, reduces PKC and cAMP-dependent protein kinase substrates phosphorylation in mouse cultured cortical neurons, but not in rat primary cortical neurons or in a striatal cell line. Furthermore, we found that incubation with chelerythrine increases pERK1/2 levels in all models studied. Moreover, our results show that chelerythrine promotes calpain activation as assessed by the cleavage of spectrin, striatal-enriched protein tyrosine phosphatase and calcineurin A. Remarkably, chelerythrine induces a concentration-dependent increase in intracellular CaThis is the first report showing that chelerythrine promotes CaChelerythrine is still marketed as a specific PKC inhibitor and extensively used in signal transduction studies. We believe that the described off-target effects should preclude its use as a PKC inhibitor in future works.

Background Thyrotoxicosis after total thyroidectomy is mostly iatrogenic. Rarely, a hyperfunctional thyroid remnant or ectopic tissue may be the cause. There are few cases of Graves’ disease arising from thyroid tissue located in the mediastinum and none in which Graves’ disease was diagnosed only after surgery. We report the case of a patient with Graves’s disease in a mediastinal thyroid mass presenting 7 years after total thyroidectomy for nontoxic goiter. Case presentation A 67-year-old Caucasian woman presented with palpitations, fatigue and weight loss. She had a history of total thyroidectomy for nontoxic multinodular goiter at the age of 60 without any signs of malignancy on microscopic examination. She had been medicated with levothyroxine 100 μg/day since the surgery without follow-up. She was tachycardic, had no cervical mass or eye involvement. Her thyroid-stimulating hormone levels were suppressed (0.000 μU/mL) and her free thyroxine (3.22 ng/dL) and free triiodothyronine (8.46 pg/mL) levels increased. Neither mediastinal enlargement nor trachea deviation was found on chest roentgenogram. Levothyroxine treatment was stopped but our patient showed no improvement on free thyroxine or free triiodothyronine 10 days later. Thyroglobulin was increased to 294 mg/mL. A cervical ultrasound scan revealed no thyroid remnant. Her anti-thyroid-stimulating hormone receptor antibodies were high (19.7 U/L). Corporal scintigraphy demonstrated increased intrathoracic radioiodine uptake. A computed tomography scan confirmed a 60 × 40 mm mediastinal mass. Methimazole 10 mg/day was started. Three months later, her thyroid function was normal and she underwent surgical resection. Microscopic examination showed thyroid tissue with no signs of malignancy. Conclusions Although thyrotoxicosis after total thyroidectomy is mostly due to excessive supplementation, true hyperthyroidism may rarely be the cause, which should be kept in mind. The presence of thyroid tissue after total thyroidectomy in our patient may correspond to a remnant or ectopic thyroid tissue that became hyperfunctional in the presence of anti- thyroid-stimulating hormone receptor antibodies.

Huntington's disease (HD) patients and mouse models show learning and memory impairment even before the onset of motor symptoms. However, the molecular events involved in this cognitive decline are still poorly understood. Here, using three different paradigms, the novel object recognition test, the T-maze spontaneous alternation task and the Morris water maze, we detected severe cognitive deficits in the R6/1 mouse model of HD before the onset of motor symptoms. When we examined the putative molecular pathways involved in these alterations, we observed hippocampal cAMP-dependent protein kinase (PKA) hyper-activation in naïve R6/1 mice compared with wild-type (WT) mice, whereas extracellular signal-regulated kinase 1/2 and calcineurin activities were not modified. Increased PKA activity resulted in hyper-phosphorylation of its substrates N-methyl-D-aspartate receptor subunit 1, Ras-guanine nucleotide releasing factor-1 and striatal-enriched protein tyrosine phosphatase, but not cAMP-responsive element binding protein or the microtubule-associated protein tau. In correlation with the over-activation of the PKA pathway, we found a down-regulation of the protein levels of some phosphodiesterase (PDE) 4 family members. Similar molecular changes were found in the hippocampus of R6/2 mice and HD patients. Furthermore, chronic treatment of WT mice with the PDE4 inhibitor rolipram up-regulated PKA activity, and induced learning and memory deficits similar to those seen in R6 mice, but had no effect on R6/1 mice cognitive impairment. Importantly, hippocampal PKA inhibition by infusion of Rp-cAMPS restored long-term memory in R6/2 mice. Thus, our results suggest that occlusion of PKA-dependent processes is one of the molecular mechanisms underlying cognitive decline in R6 animals.

Calcineurin is a serine/threonine phosphatase involved in the regulation of glutamate receptors signaling. Here, we analyzed whether the regulation of calcineurin protein levels and activity modulates the susceptibility of striatal neurons to excitotoxicity in R6/1 and R6/1:BDNF+/− mouse models of Huntington's disease. We show that calcineurin inhibition in wild-type mice drastically reduced quinolinic acid-induced striatal cell death. Moreover, calcineurin A and B were differentially regulated during disease progression with a specific reduction of calcineurin A protein levels and calcineurin activity at the onset of the disease in R6/1:BDNF+/− mice. Analysis of the conditional mouse model Tet/HD94 showed that mutant huntingtin specifically controls calcineurin A protein levels. Finally, calcineurin activation induced by intrastriatal quinolinic acid injection in R6/1 mouse was lower than in wild-type mice. Therefore, reduction of calcineurin activity by alteration of calcineurin A expression participates in the pathophysiology of Huntington's disease and contributes to the excitotoxic resistance observed in exon-1 mouse models.

Glial cell line-derived neurotrophic factor (GDNF) is widely recognized as a potent survival factor for dopaminergic neurons of the nigrostriatal pathway that degenerate in Parkinson's disease (PD). In animal models of PD, GDNF delivery to the striatum or the substantia nigra protects dopaminergic neurons against subsequent toxin-induced injury and rescues previously damaged neurons, promoting recovery of the motor function. Thus, GDNF was proposed as a potential therapy to PD aimed at slowing down, halting or reversing neurodegeneration, an issue addressed in previous reviews. However, the use of GDNF as a therapeutic agent for PD is hampered by the difficulty in delivering it to the brain. Another potential strategy is to stimulate the endogenous expression of GDNF, but in order to do that we need to understand how GDNF expression is regulated. The aim of this review is to do a comprehensive analysis of the state of the art on the control of endogenous GDNF expression in the nervous system, focusing mainly on the nigrostriatal pathway. We address the control of GDNF expression during development, in the adult brain and after injury, and how damaged neurons signal glial cells to up-regulate GDNF. Pharmacological agents or natural molecules that increase GDNF expression and show neuroprotective activity in animal models of PD are reviewed. We also provide an integrated overview of the signalling pathways linking receptors for these molecules to the induction of GDNF gene, which might also become targets for neuroprotective therapies in PD.

We recently proposed the involvement of diffusible modulators in signalling astrocytes to increase glial cell line-derived neurotrophic factor (GDNF) expression after selective dopaminergic injury by H2O2 or L-DOPA. Here we report that interleukin-1beta (IL-1beta) is involved in this crosstalk between injured neurons and astrocytes. IL-1beta was detected only in the media from challenged neuron-glia cultures. Exogenous IL-1beta did not change GDNF protein levels in astrocyte cultures, and diminished GDNF levels in neuron-glia cultures. This decrease was not due to cell loss, as assessed by the MTT assay and immunocytochemistry. Neither H2O2 nor L-DOPA induced microglia proliferation or appeared to change its activation state. The IL-1 receptor antagonist (IL-1ra) prevented GDNF up-regulation in challenged cultures, showing that IL-1beta is involved in the signalling between injured neurons and astrocytes. Since IL-1ra decreased the number of dopaminergic neurons in H2O2-treated cultures, we propose that IL-1 has a neuroprotective role in this system involving GDNF up-regulation.