Progression of Diet-Induced Diabetes in C57BL6J Mice Involves Functional Dissociation of Ca2+ Channels From Secretory Vesicles

OBJECTIVE: The aim of the study was to elucidate the cellular mechanism underlying the suppression of glucose-induced insulin secretion in mice fed a high-fat diet (HFD) for 15 weeks. RESEARCH DESIGN AND METHODS: C57BL6J mice were fed a HFD or a normal diet (ND) for 3 or 15 weeks. Plasma insulin and glucose levels in vivo were assessed by intraperitoneal glucose tolerance test. Insulin secretion in vitro was studied using static incubations and a perfused pancreas preparation. Membrane currents, electrical activity, and exocytosis were examined by patch-clamp technique measurements. Intracellular calcium concentration ([Ca(2+)](i)) was measured by microfluorimetry. Total internal reflection fluorescence microscope (TIRFM) was used for optical imaging of exocytosis and submembrane depolarization-evoked [Ca(2+)](i). The functional data were complemented by analyses of histology and gene transcription. RESULTS: After 15 weeks, but not 3 weeks, mice on HFD exhibited hyperglycemia and hypoinsulinemia. Pancreatic islet content and beta-cell area increased 2- and 1.5-fold, respectively. These changes correlated with a 20-50% reduction of glucose-induced insulin secretion (normalized to insulin content). The latter effect was not associated with impaired electrical activity or [Ca(2+)](i) signaling. Single-cell capacitance and TIRFM measurements of exocytosis revealed a selective suppression (>70%) of exocytosis elicited by short (50 ms) depolarization, whereas the responses to longer depolarizations were (500 ms) less affected. The loss of rapid exocytosis correlated with dispersion of Ca(2+) entry in HFD beta-cells. No changes in gene transcription of key exocytotic protein were observed. CONCLUSIONS: HFD results in reduced insulin secretion by causing the functional dissociation of voltage-gated Ca(2+) entry from exocytosis. These observations suggest a novel explanation to the well-established link between obesity and diabetes

Ambivalence related to potential lifestyle changes following preventive cardiovascular consultations in general practice: A qualitative study

<p>Abstract</p> <p>Background</p> <p>Motivational interviewing approaches are currently recommended in primary prevention and treatment of cardiovascular disease (CVD) in general practice in Denmark, based on an empirical and multidisciplinary body of scientific knowledge about the importance of motivation for successful lifestyle change among patients at risk of lifestyle related diseases. This study aimed to explore and describe motivational aspects related to potential lifestyle changes among patients at increased risk of CVD following preventive consultations in general practice.</p> <p>Methods</p> <p>Individual interviews with 12 patients at increased risk of CVD within 2 weeks after the consultation. Grounded theory was used in the analysis.</p> <p>Results</p> <p>Ambivalence related to potential lifestyle changes was the core motivational aspect in the interviews, even though the patients rarely verbalised this experience during the consultations. The patients experienced ambivalence in the form of conflicting feelings about lifestyle change. Analysis showed that these feelings interacted with their reflections in a concurrent process. Analysis generated a typology of five different ambivalence sub-types: perception, demand, information, priority and treatment ambivalence.</p> <p>Conclusion</p> <p>Ambivalence was a common experience in relation to motivation among patients at increased risk of CVD. Five different ambivalence sub-types were found, which clinicians may use to explore and resolve ambivalence in trying to aid patients to adopt lifestyle changes. Future research is needed to explore whether motivational interviewing and other cognitive approaches can be enhanced by exploring ambivalence in more depth, to ensure that lifestyle changes are made and sustained. Further studies with a wider range of patient characteristics are required to investigate the generalisability of the results.</p

Differential influences of environment and self-motion on place and grid cell firing

Place and grid cells in the hippocampal formation provide foundational representations of environmental location, and potentially of locations within conceptual spaces. Some accounts predict that environmental sensory information and self-motion are encoded in complementary representations, while other models suggest that both features combine to produce a single coherent representation. Here, we use virtual reality to dissociate visual environmental from physical motion inputs, while recording place and grid cells in mice navigating virtual open arenas. Place cell firing patterns predominantly reflect visual inputs, while grid cell activity reflects a greater influence of physical motion. Thus, even when recorded simultaneously, place and grid cell firing patterns differentially reflect environmental information (or ‘states’) and physical self-motion (or ‘transitions’), and need not be mutually coherent

The Making of the NEAM Tsunami Hazard Model 2018 (NEAMTHM18)

The NEAM Tsunami Hazard Model 2018 (NEAMTHM18) is a probabilistic hazard model for tsunamis generated by earthquakes. It covers the coastlines of the North-eastern Atlantic, the Mediterranean, and connected seas (NEAM). NEAMTHM18 was designed as a three-phase project. The first two phases were dedicated to the model development and hazard calculations, following a formalized decision-making process based on a multiple-expert protocol. The third phase was dedicated to documentation and dissemination. The hazard assessment workflow was structured in Steps and Levels. There are four Steps: Step-1) probabilistic earthquake model; Step-2) tsunami generation and modeling in deep water; Step-3) shoaling and inundation; Step-4) hazard aggregation and uncertainty quantification. Each Step includes a different number of Levels. Level-0 always describes the input data; the other Levels describe the intermediate results needed to proceed from one Step to another. Alternative datasets and models were considered in the implementation. The epistemic hazard uncertainty was quantified through an ensemble modeling technique accounting for alternative models’ weights and yielding a distribution of hazard curves represented by the mean and various percentiles. Hazard curves were calculated at 2,343 Points of Interest (POI) distributed at an average spacing of ∼20 km. Precalculated probability maps for five maximum inundation heights (MIH) and hazard intensity maps for five average return periods (ARP) were produced from hazard curves. In the entire NEAM Region, MIHs of several meters are rare but not impossible. Considering a 2% probability of exceedance in 50 years (ARP≈2,475 years), the POIs with MIH >5 m are fewer than 1% and are all in the Mediterranean on Libya, Egypt, Cyprus, and Greece coasts. In the North-East Atlantic, POIs with MIH >3 m are on the coasts of Mauritania and Gulf of Cadiz. Overall, 30% of the POIs have MIH >1 m. NEAMTHM18 results and documentation are available through the TSUMAPS-NEAM project website (http://www.tsumaps-neam.eu/), featuring an interactive web mapper. Although the NEAMTHM18 cannot substitute in-depth analyses at local scales, it represents the first action to start local and more detailed hazard and risk assessments and contributes to designing evacuation maps for tsunami early warning.publishedVersio

A Multistate Asian-Language Tobacco Quitline: Addressing a Disparity in Access to Care

Objectives. We conducted a dissemination and implementation study to translate an intervention protocol for Asian-language smokers from an efficacy trial into an effective and sustainable multistate service. Methods. Three state tobacco programs (in California, Colorado, and Hawaii) promoted a multistate cessation quitline to 3 Asian-language-speaking communities: Chinese, Korean, and Vietnamese. The California quitline provided counseling centrally to facilitate implementation. Three more states joined the program during the study period (January 2010–July 2012). We assessed the provision of counseling, quitting outcomes, and dissemination of the program. Results. A total of 2004 smokers called for the service, with 88.3% opting for counseling. Among those opting for counseling, the 6-month abstinence rate (18.8%) was similar to results of the earlier efficacy trial (16.4%). Conclusions. The intervention protocol, based on an efficacy trial, was successfully translated into a multistate service and further disseminated. This project paved the way for the establishment of a national quitline for Asian-language speakers, which serves as an important strategy to address disparities in access to care

Tamoxifen-Induced Cre-loxP Recombination Is Prolonged in Pancreatic Islets of Adult Mice

Tamoxifen (Tm)-inducible Cre recombinases are widely used to perform gene inactivation and lineage tracing studies in mice. Although the efficiency of inducible Cre-loxP recombination can be easily evaluated with reporter strains, the precise length of time that Tm induces nuclear translocation of CreERTm and subsequent recombination of a target allele is not well defined, and difficult to assess. To better understand the timeline of Tm activity in vivo, we developed a bioassay in which pancreatic islets with a Tm-inducible reporter (from Pdx1PB-CreERTm;R26RlacZ mice) were transplanted beneath the renal capsule of adult mice previously treated with three doses of 1 mg Tm, 8 mg Tm, or corn oil vehicle. Surprisingly, recombination in islet grafts, as assessed by expression of the β-galactosidase (β-gal) reporter, was observed days or weeks after Tm treatment, in a dose-dependent manner. Substantial recombination occurred in islet grafts long after administration of 3×8 mg Tm: in grafts transplanted 48 hours after the last Tm injection, 77.9±0.4% of β-cells were β-gal+; in β-cells placed after 1 week, 46.2±5.0% were β-gal+; after 2 weeks, 26.3±7.0% were β-gal+; and after 4 weeks, 1.9±0.9% were β-gal+. Islet grafts from mice given 3×1 mg Tm showed lower, but notable, recombination 48 hours (4.9±1.7%) and 1 week (4.5±1.9%) after Tm administration. These results show that Tm doses commonly used to induce Cre-loxP recombination may continue to label significant numbers of cells for weeks after Tm treatment, possibly confounding the interpretation of time-sensitive studies using Tm-dependent models. Therefore, investigators developing experimental approaches using Tm-inducible systems should consider both maximal recombination efficiency and the length of time that Tm-induced Cre-loxP recombination occurs

Effects of histocompatibility and host immune responses on the tumorigenicity of pluripotent stem cells

Pluripotent stem cells hold great promises for regenerative medicine. They might become useful as a universal source for a battery of new cell replacement therapies. Among the major concerns for the clinical application of stem cell-derived grafts are the risks of immune rejection and tumor formation. Pluripotency and tumorigenicity are closely linked features of pluripotent stem cells. However, the capacity to form teratomas or other tumors is not sufficiently described by inherited features of a stem cell line or a stem cell-derived graft. The tumorigenicity always depends on the inability of the recipient to reject the tumorigenic cells. This review summarizes recent data on the tumorigenicity of pluripotent stem cells in immunodeficient, syngeneic, allogeneic, and xenogeneic hosts. The effects of immunosuppressive treatment and cell differentiation are discussed. Different immune effector mechanisms appear to be involved in the rejection of undifferentiated and differentiated cell populations. Elements of the innate immune system, such as natural killer cells and the complement system, which are active also in syngeneic recipients, appear to preferentially reject undifferentiated cells. This effect could reduce the risk of tumor formation in immunocompetent recipients. Cell differentiation apparently increases susceptibility to rejection by the adaptive immune system in allogeneic hosts. The current data suggest that the immune system of the recipient has a major impact on the outcome of pluripotent stem cell transplantation, whether it is rejection, engraftment, or tumor development. This has to be considered when the results of experimental transplantation models are interpreted and even more when translation into clinics is planned

Identificación de equipos y procedimientos utilizados por fisioterapeutas brasileños para pruebas de endurance muscular inspiratoria

A avaliação da função dos músculos inspiratórios por meio do teste de endurance muscular inspiratória (EMI), definida como a capacidade de sustentação dessa tarefa ao longo do tempo, atualmente apresenta ampla variedade de instrumentos e procedimentos para sua mensuração. Este estudo teve como objetivo identificar os diferentes equipamentos, procedimentos e forma de avaliação dos testes de EMI entre fisioterapeutas brasileiros. É um estudo transversal realizado por meio de questionário enviado por correio eletrônico individualmente a cada participante. Cento e treze fisioterapeutas de diferentes regiões do país, grande parte com atuação conjunta na clínica e na docência (52,1%), responderam realizar poucas vezes a medida de EMI (48,7%). O manovacuômetro aneroide foi o aparelho mais utilizado por 42,5% dos profissionais. O clipe nasal e o bocal tubular de plástico rígido ou papel foram os acessórios mais utilizados durante o teste, correspondendo a 51,8% e 33%, respectivamente. O teste de ventilação voluntária máxima foi o mais utilizado para avaliação da endurance inspiratória, relatado por 23% dos respondentes. O teste de carga constante para avaliação da endurance foi adotado por 51,2% dos fisioterapeutas, sendo que 54,9% associaram comandos verbais à demonstração para explicação do teste. A interpretação dos valores aferidos era feita através de valores de referência por 25,7% dos entrevistados. Identificou-se que os fisioterapeutas brasileiros entrevistados não apresentaram a mesma conduta para os testes de EMI. No entanto os equipamentos, procedimentos e a forma de avaliação são utilizados com base nas diretrizes sobre o tema e de acordo com a disponibilidade de recursos do serviço.La evaluación de la función de los músculos inspiratorios a través del entrenamiento muscular inspiratorio (EMI), definida como la capacidad de sustentación de esta tarea a lo largo del tiempo, actualmente presenta una amplia variedad de instrumentos y procedimientos para su medición. Este estudio tuvo como objetivo identificar los diferentes equipos, procedimientos y forma de evaluación de las pruebas de EMI entre fisioterapeutas brasileños. Es un estudio transversal realizado por medio de un cuestionario enviado por correo electrónico a cada participante. Ciento trece fisioterapeutas de diferentes regiones del país, que en gran parte actúan a la vez en la clínica y en la enseñanza (52,1%), dijeron realizar pocas veces la medida de EMI (48,7%). El manovacuómetro aneroide fue el aparato más utilizado por el 42,5% de los profesionales. El clip nasal y la boquilla tubular de plástico rígido o papel fueron los accesorios más utilizados durante la prueba, correspondiendo al 51,8% y al 33%, respectivamente. La prueba de ventilación voluntaria máxima fue la más utilizada para la evaluación de la resistencia respiratoria, reportada por el 23% de los entrevistados. La prueba de carga constante para la evaluación de la resistencia se adoptó por el 51,2% de los fisioterapeutas, siendo que el 54,9% asoció comandos verbales a la demostración para la explicación de la prueba. La interpretación de los valores evaluados se hacía a través de valores de referencia por el 25,7% de los entrevistados. Se identificó que los fisioterapeutas brasileños entrevistados no presentaron la misma conducta para las pruebas de EMI. Sin embargo, los equipos, procedimientos y la forma de evaluación se utilizan con base en las directrices sobre el tema y de acuerdo con la disponibilidad de recursos del servicio.The assessment of inspiratory muscles through the inspiratory muscle endurance test (IME), defined as the ability to support this task over time, currently presents wide range of instruments and procedures for its measurement. This study aimed to identify the different equipment, procedures and assessments of IME tests among Brazilian physical therapists. It is a cross-sectional study carried out through a questionnaire sent individually by electronic mail to each participant. One hundred and thirteen physical therapists from different regions of the country, many practicing in the clinic and in the teaching field (52.1%), said they measured IME a few times (48.7%). The aneroid manovacuometer was used by 42.5% of the professionals. The nose clip and the hard plastic or paper tubular incentive spirometer were the most used accessories during the test, corresponding to 51.8% and 33%, respectively. The maximum voluntary ventilation test was used to assess the inspiratory endurance, reported by 23% of the respondents. The constant load test for endurance assessment was adopted by 51.2% of the physical therapists, and 54.9% associated verbal commands with the demonstration for the test application. The interpretation of the measured values was made with reference values by 25.7% of respondents. We identified that Brazilian physical therapists interviewed did not show the same conduct for IME tests. However, the equipment, procedures and assessment form are used based on the guidelines on the subject and according to the availability of resources of the service