GLP-1 metabolite GLP-1(9-36) is a systemic inhibitor of mouse and human pancreatic islet glucagon secretion.

AIMS/HYPOTHESIS: Diabetes mellitus is associated with impaired insulin secretion, often aggravated by oversecretion of glucagon. Therapeutic interventions should ideally correct both defects. Glucagon-like peptide 1 (GLP-1) has this capability but exactly how it exerts its glucagonostatic effect remains obscure. Following its release GLP-1 is rapidly degraded from GLP-1(7-36) to GLP-1(9-36). We hypothesised that the metabolite GLP-1(9-36) (previously believed to be biologically inactive) exerts a direct inhibitory effect on glucagon secretion and that this mechanism becomes impaired in diabetes. METHODS: We used a combination of glucagon secretion measurements in mouse and human islets (including islets from donors with type 2 diabetes), total internal reflection fluorescence microscopy imaging of secretory granule dynamics, recordings of cytoplasmic Ca2+ and measurements of protein kinase A activity, immunocytochemistry, in vivo physiology and GTP-binding protein dissociation studies to explore how GLP-1 exerts its inhibitory effect on glucagon secretion and the role of the metabolite GLP-1(9-36). RESULTS: GLP-1(7-36) inhibited glucagon secretion in isolated islets with an IC50 of 2.5 pmol/l. The effect was particularly strong at low glucose concentrations. The degradation product GLP-1(9-36) shared this capacity. GLP-1(9-36) retained its glucagonostatic effects after genetic/pharmacological inactivation of the GLP-1 receptor. GLP-1(9-36) also potently inhibited glucagon secretion evoked by ß-adrenergic stimulation, amino acids and membrane depolarisation. In islet alpha cells, GLP-1(9-36) led to inhibition of Ca2+ entry via voltage-gated Ca2+ channels sensitive to ω-agatoxin, with consequential pertussis-toxin-sensitive depletion of the docked pool of secretory granules, effects that were prevented by the glucagon receptor antagonists REMD2.59 and L-168049. The capacity of GLP-1(9-36) to inhibit glucagon secretion and reduce the number of docked granules was lost in alpha cells from human donors with type 2 diabetes. In vivo, high exogenous concentrations of GLP-1(9-36) (>100 pmol/l) resulted in a small (30%) lowering of circulating glucagon during insulin-induced hypoglycaemia. This effect was abolished by REMD2.59, which promptly increased circulating glucagon by >225% (adjusted for the change in plasma glucose) without affecting pancreatic glucagon content. CONCLUSIONS/INTERPRETATION: We conclude that the GLP-1 metabolite GLP-1(9-36) is a systemic inhibitor of glucagon secretion. We propose that the increase in circulating glucagon observed following genetic/pharmacological inactivation of glucagon signalling in mice and in people with type 2 diabetes reflects the removal of GLP-1(9-36)'s glucagonostatic action.

Acute/chronic inflammatory polyradiculoneuropathy.

Autoimmune neuropathy may present acutely or with a more progressive and/or relapsing and remitting course. Acute inflammatory neuropathy or Guillain-Barré syndrome (GBS) has variable presentations but by far the most common is acute inflammatory demyelinating polyradiculoneuropathy which is characterized by rapidly progressive proximal and distal symmetric weakness, sensory loss, and depressed reflexes. The most common chronic autoimmune neuropathy is chronic inflammatory demyelinating polyradiculoneuropathy, which in its most typical form is clinically similar to acute inflammatory demyelinating polyradiculoneuropathy (proximal and distal symmetric weakness, sensory loss, and depressed reflexes) but differs in that onset is much more gradual, i.e., over at least 8 weeks. While the majority of GBS cases result from a postinfectious activation of the immune system, presumably in a genetically susceptible host, less is understood regarding the etiopathogenesis of chronic inflammatory demyelinating polyradiculoneuropathy. Both acute and chronic forms of these inflammatory neuropathies are driven by some combination of innate and adaptive immune pathways, with differing contributions depending on the neuropathy subtype. Both disorders are largely clinical diagnoses, but diagnostic tools are available to confirm the diagnosis, prognosticate, detect variant forms, and rule out mimics. Given the autoimmune underpinnings of both disorders, immunosuppressive and immunomodulating treatments are typically given in both diseases; however, they differ in their response to treatment.

Somatostatin Containing δ-Cell Number Is Reduced in Type-2 Diabetes.

Recent developments suggest that increased glucagon and decreased somatostatin secretion from the pancreas contribute to hyperglycaemia in type-2 diabetes (T2D) patients. There is a huge need to understand changes in glucagon and somatostatin secretion to develop potential anti-diabetic drugs. To further describe the role of somatostatin in the pathogenesis of T2D, reliable means to detect islet δ-cells and somatostatin secretion are necessary. In this study, we first tested currently available anti-somatostatin antibodies against a mouse model that fluorescently labels δ-cells. We found that these antibodies only label 10-15% of the fluorescently labelled δ-cells in pancreatic islets. We further tested six antibodies (newly developed) that can label both somatostatin 14 (SST14) and 28 (SST28) and found that four of them were able to detect above 70% of the fluorescent cells in the transgenic islets. This is quite efficient compared to the commercially available antibodies. Using one of these antibodies (SST10G5), we compared the cytoarchitecture of mouse and human pancreatic islets and found fewer δ-cells in the periphery of human islets. Interestingly, the δ-cell number was also reduced in islets from T2D donors compared to non-diabetic donors. Finally, with the aim to measure SST secretion from pancreatic islets, one of the candidate antibodies was used to develop a direct-ELISA-based SST assay. Using this novel assay, we could detect SST secretion under low and high glucose conditions from the pancreatic islets, both in mice and humans. Overall, using antibody-based tools provided by Mercodia AB, our study indicates reduced δ-cell numbers and SST secretion in diabetic islets.

Custos de implementação do cabotegravir injetável de longa duração como profilaxia ao HIV no Brasil / Costs of implementing long-acting injectable cabotegravir as HIV prophylaxis in Brazil

Resumo O artigo descreve a estimação dos custos potenciais, sob a ótica do Ministério da Saúde (MS), da implementação do medicamento cabotegravir injetável de longa duração (CAB LA) no Sistema Único de Saúde, como alternativa para a prevenção à infecção pelo HIV e parte da estratégia nacional de prevenção combinada. Utilizou-se o instrumental analítico de cadeias de valor para elaborar a cadeia de valor do CAB LA com a identificação dos seus elos e atividades. Foram definidos três cenários de demanda com base em dados da população-alvo, variando em abrangência geográfica, e calculados os custos potenciais. A cadeia de valor do CAB LA é dividida em três grandes elos: produção, incorporação e assistência farmacêutica. Somente o último é considerado para o cálculo dos custos sob responsabilidade orçamentária do MS. Os custos potenciais são estimados em R$ 15 milhões, R$ 19 milhões e R$ 21,8 milhões, nos cenários de demanda baixa, média e alta, respectivamente. O estudo apresenta os custos potenciais para o MS, incluindo a necessidade de testes e procedimentos, de forma a orientar os gestores públicos e o próprio processo de incorporação. A ausência de preço do CAB LA é uma importante limitação para os resultados.

Abstract The article describes the estimation of the potential costs, from the perspective of the Ministry of Health (MoH), of incorporating the long-acting injectable cabotegravir (CAB LA) within the Brazilian Unified Health System, as an alternative for the prevention of HIV infection and part of the national combination prevention strategy. The analytical tools of value chains were used to elaborate the CAB LA value chain by identifying its links and activities. Three demand scenarios were defined based on target population data, varying geographic scope, and potential costs were calculated. CAB LA's value chain is divided into three major links: production, incorporation, and pharmaceutical assistance. Only the latter is considered for the calculation of costs under the budgetary responsibility of the MoH. Potential costs are estimated at R$15 million, R$19 million and R$21.8 million, in low, medium, and high demand scenarios, respectively. The study presents the potential costs for the MoH, including the need for tests and procedures, to guide public managers and the incorporation process. The lack of price for CAB LA is an important limitation of the results.

Hindbrain insulin controls feeding behavior.

OBJECTIVE: Pancreatic insulin was discovered a century ago, and this discovery led to the first lifesaving treatment for diabetes. While still controversial, nearly one hundred published reports suggest that insulin is also produced in the brain, with most focusing on hypothalamic or cortical insulin-producing cells. However, specific function for insulin produced within the brain remains poorly understood. Here we identify insulin expression in the hindbrain's dorsal vagal complex (DVC), and determine the role of this source of insulin in feeding and metabolism, as well as its response to diet-induced obesity in mice. METHODS: To determine the contribution of Ins2-producing neurons to feeding behavior in mice, we used the cross of transgenic RipHER-cre mouse and channelrhodopsin-2 expressing animals, which allowed us to optogenetically stimulate neurons expressing Ins2 in vivo. To confirm the presence of insulin expression in Rip-labeled DVC cells, in situ hybridization was used. To ascertain the specific role of insulin in effects discovered via optogenetic stimulation a selective, CNS applied, insulin receptor antagonist was used. To understand the physiological contribution of insulin made in the hindbrain a virogenetic knockdown strategy was used. RESULTS: Insulin gene expression and presence of insulin-promoter driven fluorescence in rat insulin promoter (Rip)-transgenic mice were detected in the hypothalamus, but also in the DVC. Insulin mRNA was present in nearly all fluorescently labeled cells in DVC. Diet-induced obesity in mice altered brain insulin gene expression, in a neuroanatomically divergent manner; while in the hypothalamus the expected obesity-induced reduction was found, in the DVC diet-induced obesity resulted in increased expression of the insulin gene. This led us to hypothesize a potentially divergent energy balance role of insulin in these two brain areas. To determine the acute impact of activating insulin-producing neurons in the DVC, optic stimulation of light-sensitive channelrhodopsin 2 in Rip-transgenic mice was utilized. Optogenetic photoactivation induced hyperphagia after acute activation of the DVC insulin neurons. This hyperphagia was blocked by central application of the insulin receptor antagonist S961, suggesting the feeding response was driven by insulin. To determine whether DVC insulin has a necessary contribution to feeding and metabolism, virogenetic insulin gene knockdown (KD) strategy, which allows for site-specific reduction of insulin gene expression in adult mice, was used. While chow-fed mice failed to reveal any changes of feeding or thermogenesis in response to the KD, mice challenged with a high-fat diet consumed less food. No changes in body weight were identified, possibly resulting from compensatory reduction in thermogenesis. CONCLUSIONS: Together, our data suggest an important role for hindbrain insulin and insulin-producing cells in energy homeostasis.

Gap junction coupling and islet delta-cell function in health and disease.

The pancreatic islets contain beta-cells and alpha-cells, which are responsible for secreting two principal gluco-regulatory hormones; insulin and glucagon, respectively. However, they also contain delta-cells, a relatively sparse cell type that secretes somatostatin (SST). These cells have a complex morphology allowing them to establish an extensive communication network throughout the islet, despite their scarcity. Delta-cells are electrically excitable cells, and SST secretion is released in a glucose- and KATP-dependent manner. SST hyperpolarises the alpha-cell membrane and suppresses exocytosis. In this way, islet SST potently inhibits glucagon release. Recent studies investigating the activity of delta-cells have revealed they are electrically coupled to beta-cells via gap junctions, suggesting the delta-cell is more than just a paracrine inhibitor. In this Review, we summarize delta-cell morphology, function, and the role of SST signalling for regulating islet hormonal output. A distinguishing feature of this Review is that we attempt to use the discovery of this gap junction pathway, together with what is already known about delta-cells, to reframe the role of these cells in both health and disease. In particular, we argue that the discovery of gap junction communication between delta-cells and beta-cells provides new insights into the contribution of delta-cells to the islet hormonal defects observed in both type 1 and type 2 diabetes. This reappraisal of the delta-cell is important as it may offer novel insights into how the physiology of this cell can be utilised to restore islet function in diabetes.

Controversial aspects of the concept of health needs and their impact on the accessibility of medicine and health services. / Aspectos controversos do conceito de necessidades de saúde e seus reflexos sobre a acessibilidade de medicamentos e serviços de saúde.

This article aimed to present the problems related to accessibility of health services by re-reading four case studies which illustrate the different dimensions of the definition of health needs and their impact on the accessibility of medicine and health services. The theoretical model of Vargas-Peláez et al.1, which allows a better understanding of the complexity of the definition of health needs and its impact on the demand for medicines and services, was adopted to re-read the case studies on the prices of patented medicines, the models of public provision, hemodynamic services, and prescription of anxiolytics. The results may shed some light on the complexity of the challenges to achieve health rights in a peripheral capitalist society where the production and distribution of goods and services is organized from the perspective of the market, even though public policies seek to regulate them. In this sense, it seems essential that the State plays a major role in guaranteeing equality in the achievement of social rights, not only influencing the industrial sector in reducing the prices of medicines and improving their supply, but also guaranteeing access to medicine and health services.

O objetivo do artigo é mostrar os problemas relativos à acessibilidade de serviços de saúde relendo quatro estudos de caso que ilustram as diferentes dimensões da definição de necessidades de saúde e os seus reflexos sobre a acessibilidade dos medicamentos e dos serviços de saúde. O modelo teórico de Vargas-Peláez et al.1, que permite um melhor entendimento da complexidade da definição das necessidades de saúde e os seus reflexos sobre a demanda de medicamentos e de serviços, foi adotado para reler os estudos de caso sobre preços dos medicamentos patenteados, os modelos de provisão pública, os serviços de hemodinâmica e a prescrição de ansiolíticos. Os resultados permitem iluminar a complexidade dos desafios presentes para obtenção dos direitos de saúde numa sociedade capitalista periférica em que a produção e a distribuição dos bens e serviços são organizadas na perspectiva do mercado ainda que as políticas públicas busquem regulá-las. Neste sentido, parece imprescindível que o Estado tenha um papel preponderante na garantia da equidade para o alcance dos direitos sociais, não só estimulando a indústria para redução dos preços dos medicamentos e melhoria de sua provisão, como garantindo acesso aos medicamentos e serviços de saúde.

Arginine-vasopressin mediates counter-regulatory glucagon release and is diminished in type 1 diabetes.

Insulin-induced hypoglycemia is a major treatment barrier in type-1 diabetes (T1D). Accordingly, it is important that we understand the mechanisms regulating the circulating levels of glucagon. Varying glucose over the range of concentrations that occur physiologically between the fed and fuel-deprived states (8 to 4 mM) has no significant effect on glucagon secretion in the perfused mouse pancreas or in isolated mouse islets (in vitro), and yet associates with dramatic increases in plasma glucagon. The identity of the systemic factor(s) that elevates circulating glucagon remains unknown. Here, we show that arginine-vasopressin (AVP), secreted from the posterior pituitary, stimulates glucagon secretion. Alpha-cells express high levels of the vasopressin 1b receptor (V1bR) gene (Avpr1b). Activation of AVP neurons in vivo increased circulating copeptin (the C-terminal segment of the AVP precursor peptide) and increased blood glucose; effects blocked by pharmacological antagonism of either the glucagon receptor or V1bR. AVP also mediates the stimulatory effects of hypoglycemia produced by exogenous insulin and 2-deoxy-D-glucose on glucagon secretion. We show that the A1/C1 neurons of the medulla oblongata drive AVP neuron activation in response to insulin-induced hypoglycemia. AVP injection increased cytoplasmic Ca2+ in alpha-cells (implanted into the anterior chamber of the eye) and glucagon release. Hypoglycemia also increases circulating levels of AVP/copeptin in humans and this hormone stimulates glucagon secretion from human islets. In patients with T1D, hypoglycemia failed to increase both copeptin and glucagon. These findings suggest that AVP is a physiological systemic regulator of glucagon secretion and that this mechanism becomes impaired in T1D.

Aspectos controversos do conceito de necessidades de saúde e seus reflexos sobre a acessibilidade de medicamentos e serviços de saúde / Controversial aspects of the concept of health needs and their impact on the accessibility of medicine and health services

Resumo O objetivo do artigo é mostrar os problemas relativos à acessibilidade de serviços de saúde relendo quatro estudos de caso que ilustram as diferentes dimensões da definição de necessidades de saúde e os seus reflexos sobre a acessibilidade dos medicamentos e dos serviços de saúde. O modelo teórico de Vargas-Peláez et al.1, que permite um melhor entendimento da complexidade da definição das necessidades de saúde e os seus reflexos sobre a demanda de medicamentos e de serviços, foi adotado para reler os estudos de caso sobre preços dos medicamentos patenteados, os modelos de provisão pública, os serviços de hemodinâmica e a prescrição de ansiolíticos. Os resultados permitem iluminar a complexidade dos desafios presentes para obtenção dos direitos de saúde numa sociedade capitalista periférica em que a produção e a distribuição dos bens e serviços são organizadas na perspectiva do mercado ainda que as políticas públicas busquem regulá-las. Neste sentido, parece imprescindível que o Estado tenha um papel preponderante na garantia da equidade para o alcance dos direitos sociais, não só estimulando a indústria para redução dos preços dos medicamentos e melhoria de sua provisão, como garantindo acesso aos medicamentos e serviços de saúde.

Abstract This article aimed to present the problems related to accessibility of health services by re-reading four case studies which illustrate the different dimensions of the definition of health needs and their impact on the accessibility of medicine and health services. The theoretical model of Vargas-Peláez et al.1, which allows a better understanding of the complexity of the definition of health needs and its impact on the demand for medicines and services, was adopted to re-read the case studies on the prices of patented medicines, the models of public provision, hemodynamic services, and prescription of anxiolytics. The results may shed some light on the complexity of the challenges to achieve health rights in a peripheral capitalist society where the production and distribution of goods and services is organized from the perspective of the market, even though public policies seek to regulate them. In this sense, it seems essential that the State plays a major role in guaranteeing equality in the achievement of social rights, not only influencing the industrial sector in reducing the prices of medicines and improving their supply, but also guaranteeing access to medicine and health services.

COMPLEXITY OF PEDIATRIC CHRONIC DISEASE: CROSS-SECTIONAL STUDY WITH 16,237 PATIENTS FOLLOWED BY MULTIPLE MEDICAL SPECIALTIES.

OBJECTIVE: To assess demographic data and characteristics of children and adolescents with pediatric chronic diseases (PCD), according to the number of specialties/patient. METHODS: We performed a cross-sectional study with 16,237 PCD patients at outpatient clinics in one year. Data were analyzed by an electronic data system, according to the number of physician appointments for PCD. This study assessed: demographic data, follow-up characteristics, types of medical specialty, diagnosis (International Statistical Classification of Diseases and Related Health Problems - ICD-10), number of day hospital clinic visits, and acute complications. RESULTS: Patients followed by ≥3 specialties simultaneously showed a significantly higher duration of follow-up compared to those followed by ≤2 specialties [2.1 (0.4-16.4) vs. 1.4 (0.1-16.2) years; p<0.001] and a higher number of appointments in all specialties. The most prevalent medical areas in patients followed by ≥3 specialties were: Psychiatry (Odds Ratio - OR=8.0; confidence interval of 95% - 95%CI 6-10.7; p<0.001), Palliative/Pain Care (OR=7.4; 95%CI 5.7-9.7; p<0.001), Infectious Disease (OR=7.0; 95%CI 6.4-7.8; p<0.001) and Nutrology (OR=6.9; 95%CI 5.6-8.4; p<0.001). Logistic regressions demonstrated that PCD patients followed by ≥3 specialties were associated with high risk for: number of appointments/patient (OR=9.2; 95%CI 8.0-10.5; p<0.001), day hospital clinic visits (OR=4.8; 95%CI 3.8-5.9; p<0.001), emergency department visits (OR=3.2; 95%CI 2.9-3.5; p<0.001), hospitalizations (OR=3.0; 95%CI 2.7-3.3; p<0.001), intensive care admissions (OR=2.5; 95%CI 2.1-3.0; p<0.001), and deaths (OR=2.8; 95%CI 1.9-4.0; p<0.001). The diagnosis of asthma, obesity, chronic pain, and transplant was significantly higher in patients followed by ≥3 specialties. CONCLUSIONS: The present study showed that PCD patients who required simultaneous care from multiple medical specialties had complex and severe diseases, with specific diagnoses.

Complexity of pediatric chronic disease: cross-sectional study with 16,237 patients followed by multiple medical specialties / Complexidade da doença crônica pediátrica: estudo tranversal com 16.237 pacientes seguidos por múltiplas especialidades médicas

ABSTRACT Objective: To assess demographic data and characteristics of children and adolescents with pediatric chronic diseases (PCD), according to the number of specialties/patient. Methods: We performed a cross-sectional study with 16,237 PCD patients at outpatient clinics in one year. Data were analyzed by an electronic data system, according to the number of physician appointments for PCD. This study assessed: demographic data, follow-up characteristics, types of medical specialty, diagnosis (International Statistical Classification of Diseases and Related Health Problems - ICD-10), number of day hospital clinic visits, and acute complications. Results: Patients followed by ≥3 specialties simultaneously showed a significantly higher duration of follow-up compared to those followed by ≤2 specialties [2.1 (0.4-16.4) vs. 1.4 (0.1-16.2) years; p<0.001] and a higher number of appointments in all specialties. The most prevalent medical areas in patients followed by ≥3 specialties were: Psychiatry (Odds Ratio - OR=8.0; confidence interval of 95% - 95%CI 6-10.7; p<0.001), Palliative/Pain Care (OR=7.4; 95%CI 5.7-9.7; p<0.001), Infectious Disease (OR=7.0; 95%CI 6.4-7.8; p<0.001) and Nutrology (OR=6.9; 95%CI 5.6-8.4; p<0.001). Logistic regressions demonstrated that PCD patients followed by ≥3 specialties were associated with high risk for: number of appointments/patient (OR=9.2; 95%CI 8.0-10.5; p<0.001), day hospital clinic visits (OR=4.8; 95%CI 3.8-5.9; p<0.001), emergency department visits (OR=3.2; 95%CI 2.9-3.5; p<0.001), hospitalizations (OR=3.0; 95%CI 2.7-3.3; p<0.001), intensive care admissions (OR=2.5; 95%CI 2.1-3.0; p<0.001), and deaths (OR=2.8; 95%CI 1.9-4.0; p<0.001). The diagnosis of asthma, obesity, chronic pain, and transplant was significantly higher in patients followed by ≥3 specialties. Conclusions: The present study showed that PCD patients who required simultaneous care from multiple medical specialties had complex and severe diseases, with specific diagnoses.

RESUMO Objetivo: Avaliar dados demográficos e características de crianças e adolescentes com doenças crônicas pediátricas, de acordo com o número de especialidades/paciente. Métodos: Realizou-se um estudo transversal com 16.237 pacientes com doenças crônicas pediátricas durante um ano. A análise foi feita em um sistema eletrônico, de acordo com número de consultas médicas para doenças crônicas pediátricas. Este estudo avaliou dados demográficos, características do seguimento, tipos de especialidades médicas, diagnóstico (10ª Revisão da Classificação Estatística Internacional de Doenças e Problemas Relacionados com a Saúde - CID-10), número de visitas e complicações agudas. Resultados: Os pacientes acompanhados por três ou mais especialidades simultaneamente tiveram seguimento de maior duração comparados com aqueles seguidos por ≤2 especialidades [2,1 (0,4-16,4) vs. 1,4 (0,1-16,2) anos; p<0,001], bem como maior número de consultas em todas as especialidades. As áreas médicas mais comuns em pacientes acompanhados por ≥3 especialidades foram: psiquiatria (Odds Ratio - OR=8,0; intervalo de confiança de 95% - IC95% 6-10,7; p<0,001); dor/cuidados paliativos (OR=7,4; IC95% 5,7-9,7; p<0,001); doenças infecciosas (OR=7,0; IC95% 6,4-7,8; p<0,001); nutrologia (OR=6,9; IC95% 5,6-8,4; p<0,001). As regressões logísticas mostraram que os pacientes com doenças crônicas pediátricas seguidos por ≥3 especialidades tinham alto risco para: maior número de consultas/paciente (OR=9,2; IC95% 8,0-10,5; p<0,001); atendimentos em hospital-dia (OR=4,8; 95%IC3,8-5,9; p<0,001); atendimentos em pronto-socorro (OR=3,2; IC95% 2,9-3,5; p<0,001); hospitalizações (OR=3,0; IC95%2,7-3,3; p<0,001); internação em terapia intensiva (OR=2,5; IC95% 2,1-3,0; p<0,001); óbitos (OR=2,8; IC95%1,9-4,0; p<0,001). Os diagnósticos de asma, obesidade, dor crônica, transplante e infecção do trato urinário foram mais frequentes nos pacientes seguidos por três ou mais especialidades. Conclusões: O presente estudo mostrou que pacientes com doenças crônicas pediátricas que necessitaram de múltiplas especialidades médicas simultaneamente apresentavam doenças complexas e graves, com diagnósticos específicos.

Imaging Calcium Dynamics in Subpopulations of Mouse Pancreatic Islet Cells.

Pancreatic islet hormones regulate blood glucose homeostasis. Changes in blood glucose induce oscillations of cytosolic calcium in pancreatic islet cells that trigger secretion of three main hormones: insulin (from ß-cells), glucagon (α-cells) and somatostatin (δ-cells). ß-Cells, which make up the majority of islet cells and are electrically coupled to each other, respond to the glucose stimulus as one single entity. The excitability of the minor subpopulations, α-cells and δ-cells (making up around 20% (30%) and 4% (10%) of the total rodent1 (human2) islet cell numbers, respectively) is less predictable and is therefore of special interest. Calcium sensors are delivered into the peripheral layer of cells within the isolated islet. The islet or a group of islets is then immobilized and imaged using a fluorescence microscope. The choice of the imaging mode is between higher throughput (wide-field) and better spatial resolution (confocal). Conventionally, laser scanning confocal microscopy is used for imaging tissue, as it provides the best separation of the signal between the neighboring cells. A wide-field system can be utilized too, if the contaminating signal from the dominating population of ß-cells is minimized. Once calcium dynamics in response to specific stimuli have been recorded, data are expressed in numerical form as fluorescence intensity vs. time, normalized to the initial fluorescence and baseline-corrected, to remove the effects linked to bleaching of the fluorophore. Changes in the spike frequency or partial area under the curve (pAUC) are computed vs. time, to quantify the observed effects. pAUC is more sensitive and quite robust whereas spiking frequency provides more information on the mechanism of calcium increase. Minor cell subpopulations can be identified using functional responses to marker compounds, such as adrenaline and ghrelin, that induce changes in cytosolic calcium in a specific populations of islet cells.

Leptomeningeal metastases in glioma: The Memorial Sloan Kettering Cancer Center experience.

OBJECTIVE: To perform a retrospective analysis examining the incidence and prognosis of glioma patients with leptomeningeal disease (LMD) at Memorial Sloan Kettering Cancer Center over a 15-year period and correlate these findings with clinicopathologic characteristics. METHODS: We conducted a retrospective review of glioma patients with LMD at Memorial Sloan Kettering Cancer Center diagnosed from 2001 to 2016. Patients were identified through a keyword search of their electronic medical record and by ICD-9 codes. RESULTS: One hundred three patients were identified with disseminated LMD and 85 patients with subependymal spread of disease, 4.7% of all patients with glioma. These cohorts were analyzed separately for time to development of disseminated LMD/subependymal LMD, median overall survival, and survival from LMD diagnosis. Patients were pooled for subsequent analyses (n = 188) because of comparable clinical behavior. LMD was present at glioma diagnosis in 10% of patients. In the remaining 90% of patients diagnosed at recurrence, time to LMD diagnosis, survival after LMD diagnosis, and overall survival varied by original histology. Patients with oligodendroglioma had a median survival of 10.8 (range 1.8-67.7) months, astrocytoma 6.5 (0.1-28.5) months, and glioblastoma 3.8 (0.1-32.6) months after LMD diagnosis. In addition, we found that treatment of LMD was associated with superior performance status and increased survival. CONCLUSION: Patients with LMD diagnosed at relapse may not have decreased overall survival as compared to historical controls with parenchymal relapse and may benefit from treatment.

Pediatric chronic patients at outpatient clinics: a study in a Latin American University Hospital / Pacientes pediátricos crônicos em clínicas ambulatoriais: estudo em um hospital universitário da América Latina

Abstract Objective: To describe the characteristics of children and adolescentes with chronic diseases of outpatient clinics at a tertiary university hospital. Methods: A cross-sectional study was performed with 16,237 patients with chronic diseases followed-up in one year. The data were collected through the electronic system, according to the number of physician appointments in 23 pediatric specialties. Patients were divided in two groups: children (0-9 years) and adolescents (10-19 years). Early (10-14 years) and late (15-19 years) adolescent groups were also analyzed. Results: Of the total sample, 56% were children and 46% were adolescents. The frequencies of following pediatric specialties were significantly higher in adolescents when compared with children: cardiology, endocrinology, hematology, nephrology/renal transplantation, neurology, nutrology, oncology, palliative and pain care, psychiatry, and rheumatology (p < 0.05). The frequencies of emergency service visits (30% vs. 17%, p < 0.001), hospitalizations (23% vs. 11%, p < 0.001), intensive care unit admissions (6% vs. 2%, p < 0.001), and deaths (1% vs. 0.6%, p = 0.002) were significantly lower in adolescents than in children. However, the number of physician appointments (≥13) per patient was also higher in the adolescent group (5% vs. 6%, p = 0.018). Further analysis comparison between early and late adolescents revealed that the first group had significantly more physician appointments (35% vs. 32%, p = 0.025), and required more than two pediatric specialties (22% vs. 21%, p = 0.047). Likewise, the frequencies of emergency service visits (19% vs. 14%, p < 0.001) and hospitalizations (12% vs. 10%, p = 0.035) were higher in early adolescents. Conclusions: This study evaluated a large population in a Latin American hospital and suggested that early adolescents with chronic diseases required many appointments, multiple specialties and hospital admissions.

Resumo Objetivo: Descrever características de crianças e adolescentes com doenças crônicas de clínicas ambulatoriais em um hospital universitário terciário. Métodos: Um estudo transversal foi realizado com 16.237 pacientes com doenças crônicas acompanhados em um ano. Os dados foram coletados por meio de dados do sistema eletrônico de acordo com o número de consultas médicas em 23 especialidades pediátricas. Os pacientes foram divididos em dois grupos: crianças (0-9 anos) e adolescentes (10-19 anos). Também foram analisados grupos de jovens adolescentes (10-14 anos) e adolescentes mais velhos (15-19 anos). Resultados: 54% eram crianças e 46% eram adolescentes. As frequências das seguintes especialidades pediátricas foram significativamente maiores em adolescentes em comparação a crianças: cardiologia, endocrinologia, hematologia, nefrologia/transplante renal, neurologia, nutrologia, oncologia, cuidados paliativos e cuidado da dor, psiquiatria e reumatologia (p < 0,05). As frequências de visitas a serviços de emergência (30%, em comparação a 17%, p < 0,001), internações (23%, em comparação a 11%, p < 0,001), internações em unidade de terapia intensiva (6%, em comparação a 2%, p < 0,001) e óbitos (1%, em comparação a 0,6%, p = 0,002) foram significativamente menores em adolescentes do que em crianças. Contudo, o número de consultas médicas (≥ 13) por paciente (também) foi maior em grupos de adolescentes (5%, em comparação a 6%, p = 0,018). A comparação de análises adicionais entre jovens adolescentes e adolescentes mais velhos revelou que o primeiro grupo apresentou um número significativamente maior de consultas médicas (35%, em comparação a 32%, p = 0,025) e precisou de mais de duas especialidades pediátricas (22%, em comparação a 21%, p = 0,047). Da mesma forma, as frequências de visitas a serviços de emergência (19%, em comparação a 14%, p < 0,001) e internações (12%, em comparação a 10%, p = 0,035) foram maiores em jovens adolescentes. Conclusões: Este estudo avaliou uma grande população em um hospital da América Latina e sugeriu que jovens adolescentes com doenças crônicas precisaram de muitas consultas, diversas especialidades e internações hospitalares.

GLP-1 suppresses glucagon secretion in human pancreatic alpha-cells by inhibition of P/Q-type Ca2+ channels.

Glucagon is the body's main hyperglycemic hormone, and its secretion is dysregulated in type 2 diabetes mellitus (T2DM). The incretin hormone glucagon-like peptide-1 (GLP-1) is released from the gut and is used in T2DM therapy. Uniquely, it both stimulates insulin and inhibits glucagon secretion and thereby lowers plasma glucose levels. In this study, we have investigated the action of GLP-1 on glucagon release from human pancreatic islets. Immunocytochemistry revealed that only <0.5% of the α-cells possess detectable GLP-1R immunoreactivity. Despite this, GLP-1 inhibited glucagon secretion by 50-70%. This was due to a direct effect on α-cells, rather than paracrine signaling, because the inhibition was not reversed by the insulin receptor antagonist S961 or the somatostatin receptor-2 antagonist CYN154806. The inhibitory effect of GLP-1 on glucagon secretion was prevented by the PKA-inhibitor Rp-cAMPS and mimicked by the adenylate cyclase activator forskolin. Electrophysiological measurements revealed that GLP-1 decreased action potential height and depolarized interspike membrane potential. Mathematical modeling suggests both effects could result from inhibition of P/Q-type Ca2+ channels. In agreement with this, GLP-1 and ω-agatoxin (a blocker of P/Q-type channels) inhibited glucagon secretion in islets depolarized by 70 mmol/L [K+ ]o , and these effects were not additive. Intracellular application of cAMP inhibited depolarization-evoked exocytosis in individual α-cells by a PKA-dependent (Rp-cAMPS-sensitive) mechanism. We propose that inhibition of glucagon secretion by GLP-1 involves activation of the few GLP-1 receptors present in the α-cell membrane. The resulting small elevation of cAMP leads to PKA-dependent inhibition of P/Q-type Ca2+ channels and suppression of glucagon exocytosis.

Tension pneumocephalus mimicking septic shock: a case report.

Tension pneumocephalus can lead to rapid neurologic deterioration. We report for the first time its association with aseptic systemic inflammatory response syndrome mimicking septic shock and the efficacy of prompt neurosurgical intervention and critical care support in treating this condition. A 64-year-old man underwent 2-stage olfactory groove meningioma resection. The patient developed altered mental status and gait instability on postoperative day 6. Imaging showed significant pneumocephalus. The patient subsequently developed worsening mental status, respiratory failure, and profound shock requiring multiple vasopressors. Bedside needle decompression, identification and repair of the cranial fossa defect, and critical care support led to improved mental status and reversal of shock and multiorgan dysfunction. Thorough evaluation revealed no evidence of an underlying infection. In this case, tension pneumocephalus incited an aseptic systemic inflammatory response syndrome mimicking septic shock. Prompt neurosurgical correction of pneumocephalus and critical care support not only improved neurologic status, but also reversed shock. Such a complication indicates the importance of close monitoring of patients with progressive pneumocephalus.

Sense-Antisense lncRNA Pair Encoded by Locus 6p22.3 Determines Neuroblastoma Susceptibility via the USP36-CHD7-SOX9 Regulatory Axis.

Trait-associated loci often map to genomic regions encoding long noncoding RNAs (lncRNAs), but the role of these lncRNAs in disease etiology is largely unexplored. We show that a pair of sense/antisense lncRNA (6p22lncRNAs) encoded by CASC15 and NBAT1 located at the neuroblastoma (NB) risk-associated 6p22.3 locus are tumor suppressors and show reduced expression in high-risk NBs. Loss of functional synergy between 6p22lncRNAs results in an undifferentiated state that is maintained by a gene-regulatory network, including SOX9 located on 17q, a region frequently gained in NB. 6p22lncRNAs regulate SOX9 expression by controlling CHD7 stability via modulating the cellular localization of USP36, encoded by another 17q gene. This regulatory nexus between 6p22.3 and 17q regions may lead to potential NB treatment strategies.

Lipophilicity predicts the ability of nonsulphonylurea drugs to block pancreatic beta-cell KATP channels and stimulate insulin secretion; statins as a test case.

AIMS: KATP ion channels play a key role in glucose-stimulated insulin secretion. However, many drugs block KATP as "off targets" leading to hyperinsulinaemia and hypoglycaemia. As such drugs are often lipophilic, the aim was to examine the relationship between drug lipophilicity (P) and IC 50 for KATP block and explore if the IC 50's of statins could be predicted from their lipophilicity and whether this would allow one to forecast their acute action on insulin secretion. MATERIALS AND METHODS: A meta-analysis of 26 lipophilic, nonsulphonylurea, blockers of KATP was performed. From this, the IC 50's for pravastatin and simvastatin were predicted and then tested experimentally by exploring their effects on KATP channel activity via patch-clamp measurement, calcium imaging and insulin secretion in murine beta cells and islets. RESULTS: Nonsulphonylurea drugs inhibited KATP channels with a Log IC 50 linearly related to their logP. Simvastatin blocked KATP with an IC 50 of 25 nmol/L, a value independent of cytosolic factors, and within the range predicted by its lipophilicity (21-690 nmol/L). 10 µmol/L pravastatin, predicted IC 50 0.2-12 mmol/L, was without effect on the KATP channel. At 10-fold therapeutic levels, 100 nmol/L simvastatin depolarized the beta-cell membrane potential and stimulated Ca2+ influx but did not affect insulin secretion; the latter could be explained by serum binding. CONCLUSIONS: The logP of a drug can aid prediction for its ability to block beta-cell KATP ion channels. However, although the IC 50 for the block of KATP by simvastatin was predicted, the difference between this and therapeutic levels, as well as serum sequestration, explains why hypoglycaemia is unlikely to be observed with acute use of this statin.

Pediatric chronic patients at outpatient clinics: a study in a Latin American University Hospital.

OBJECTIVE: To describe the characteristics of children and adolescentes with chronic diseases of outpatient clinics at a tertiary university hospital. METHODS: A cross-sectional study was performed with 16,237 patients with chronic diseases followed-up in one year. The data were collected through the electronic system, according to the number of physician appointments in 23 pediatric specialties. Patients were divided in two groups: children (0-9 years) and adolescents (10-19 years). Early (10-14 years) and late (15-19 years) adolescent groups were also analyzed. RESULTS: Of the total sample, 56% were children and 46% were adolescents. The frequencies of following pediatric specialties were significantly higher in adolescents when compared with children: cardiology, endocrinology, hematology, nephrology/renal transplantation, neurology, nutrology, oncology, palliative and pain care, psychiatry, and rheumatology (p<0.05). The frequencies of emergency service visits (30% vs. 17%, p<0.001), hospitalizations (23% vs. 11%, p<0.001), intensive care unit admissions (6% vs. 2%, p<0.001), and deaths (1% vs. 0.6%, p=0.002) were significantly lower in adolescents than in children. However, the number of physician appointments (≥13) per patient was also higher in the adolescent group (5% vs. 6%, p=0.018). Further analysis comparison between early and late adolescents revealed that the first group had significantly more physician appointments (35% vs. 32%, p=0.025), and required more than two pediatric specialties (22% vs. 21%, p=0.047). Likewise, the frequencies of emergency service visits (19% vs. 14%, p<0.001) and hospitalizations (12% vs. 10%, p=0.035) were higher in early adolescents. CONCLUSIONS: This study evaluated a large population in a Latin American hospital and suggested that early adolescents with chronic diseases required many appointments, multiple specialties and hospital admissions.

Occult gastrointestinal bleeding is a common finding in dogs with chronic kidney disease.

BACKGROUND: The risk of occult gastrointestinal bleeding (OGIB) is known to be increased among human dialysis patients suffering from end-stage renal disease. However, there are no studies to date that investigate the incidence of OGIB in either dogs or people with chronic kidney disease (CKD), irrespective of dialysis. OBJECTIVES: The purpose of the study was to determine whether the incidence of OGIB is greater in dogs with CKD as compared to a control population, and if this pathology is associated with changes in serum variables related to iron metabolism. METHODS: Fecal occult bleeding was evaluated in 10 healthy dogs and 30 CKD dogs. Test results were compared to indicators of blood loss and/or iron metabolism. RESULTS: Dogs with CKD had a significantly higher incidence of OGIB than the control group (P < .0001). While 80% of dogs with stage 2 CKD did not exhibit anemia, 90% tested positive for OGIB. Similarly, subjects with stage 4 CKD had more significant blood loss than either stage 2 (P = .0071) or stage 3 CKD (P = .0385). Serum hemoglobin, transferrin, and iron concentrations in the CKD group were statistically lower than in the control group (P < .0001) and correlated with fecal occult bleeding (r = -.61; r = -.40; r = -.44, respectively), as well as serum creatinine concentrations (P < .0001, r = .64). CONCLUSIONS: This preliminary study suggests that OGIB is a common clinical finding among dogs with CKD, even in the early stages of the disease process. Therefore, fecal occult blood tests may be useful as an indication for gastroprotective agents in the treatment plan.