A Novel Missense Mutation, I890T, in the Pore Region of Cardiac Sodium Channel Causes Brugada Syndrome

Brugada syndrome (BrS) is a life-threatening, inherited arrhythmogenic syndrome associated with autosomal dominant mutations in SCN5A, the gene encoding the cardiac Na��� channel alpha subunit (Na���1.5). The aim of this work was to characterize the functional alterations caused by a novel SCN5A mutation, I890T, and thus establish whether this mutation is associated with BrS. The mutation was identified by direct sequencing of SCN5A from the proband���s DNA. Wild-type (WT) or I890T Na���1.5 channels were heterologously expressed in human embryonic kidney cells. Sodium currents were studied using standard whole cell patch-clamp protocols and immunodetection experiments were performed using an antibody against human Na���1.5 channel. A marked decrease in current density was observed in cells expressing the I890T channel (from -52.0 �� 6.5 pA/pF, n=15 to 35.9 �� 3.4 pA/pF, n = 22, at -20 mV, WT and I890T, respectively). Moreover, a positive shift of the activation curve was identified (V�� =-32.0 �� 0.3 mV, n = 18, and -27.3 �� 0.3 mV, n = 22, WT and I890T, respectively). No changes between WT and I890T currents were observed in steady-state inactivation, time course of inactivation, slow inactivation or recovery from inactivation parameters. Cell surface protein biotinylation analyses confirmed that Nav1.5 channel membrane expression levels were similar in WT and I890T cells. In summary, our data reveal that the I890T mutation, located within the pore of Nav1.5, causes an evident loss-of-function of the channel. Thus, the BrS phenotype observed in the proband is most likely due to this mutation

Separation of Gas Bubbles from Circulation Waters and Pulp Suspensions in Open Channel Flow

The objective of this thesis was to study the removal of gases from paper mill circulation waters experimentally and to provide data for CFD modeling. Flow and bubble size measurements were carried out in a laboratory scale open gas separation channel. Particle Image Velocimetry (PIV) technique was used to measure the gas and liquid flow fields, while bubble size measurements were conducted using digital imaging technique with back light illumination. Samples of paper machine waters as well as a model solution were used for the experiments. The PIV results show that the gas bubbles near the feed position have the tendency to escape from the circulation channel at a faster rate than those bubbles which are further away from the feed position. This was due to an increased rate of bubble coalescence as a result of the relatively larger bubbles near the feed position. Moreover, a close similarity between the measured slip velocities of the paper mill waters and that of literature values was obtained. It was found that due to dilution of paper mill waters, the observed average bubble size was considerably large as compared to the average bubble sizes in real industrial pulp suspension and circulation waters. Among the studied solutions, the model solution has the highest average drag coefficient value due to its relatively high viscosity. The results were compared to a 2D steady sate CFD simulation model. A standard Euler-Euler k-�� turbulence model was used in the simulations. The channel free surface was modeled as a degassing boundary. From the drag models used in the simulations, the Grace drag model gave velocity fields closest to the experimental values. In general, the results obtained from experiments and CFD simulations are in good qualitative agreement.

Towards a Strategic Sales Channel Partnership: A Case Study from the IT Services Industry

Strategic partnerships have become a key to competitive advantage and success in a dynamic, global business environment. Partnering provides a strategic response to complex offerings that need multiple sources of technology and knowledge, allowing companies to offer a wider range of services and solutions to meet their customers��� needs. Companies that collaborate with strategic partners in sales channels may significantly grow their business and improve their prospects of winning major contracts. As a consequence, companies are increasingly transforming their go-to-market strategies and sales channel structures to align with the need to create added value to customers together with a business partner. The research objective of this case study is to review and assess the success of an established sales channel partnership in IT services industry and to find ways how to develop it towards a strategic collaboration. The research consists of two main parts. The first part reviews the literature, concluding with the identification of the critical success factors for partnering. The second part sets out for the case findings, focusing on how the success of the established sales channel partnership is perceived by key executives within the partner organizations, and further what actions are required to make the sales channel partnership and joint go-to-market more strategic.

Role of the canonical transient receptor potential channel 2 (TRPC2) in thyroid cell function

Kalciumjonen reglerar flera processer i celler s��som transkribering av gener, celldelning, cellernas r��rlighet och celld��d. D��rf��r har cellerna utvecklat m��nga mekanismer f��r att reglera den intracellul��ra kalciumkoncentrationen. Kalciumkanaler spelar en viktig roll i denna regleringsprocess. TRPC-kanalerna (eng. canonical transient receptor potential) ��r en familj av jonkanaler med sju medlemmar (TRPC1-7) vars regleringsmekanismer och fysiologiska roller ��r varierande. TRPC2-kanalens fysiologiska signifikans, samt hur kanalen regleras, ��r d��ligt karakteriserad. F��r f��rsta g��ngen, rapporterar vi n��rvaron av TRPC2 kanalen i r��ttans sk��ldk��rtelceller samt prim��ra sk��ldk��rtelceller fr��n r��tta. Hos gnagare har TRPC2 antagits vara exklusivt uttryckt i det vomeronasala organet. F��r att unders��ka den fysiologiska betydelsen av kanalen, har vi utvecklat stabila celler med nedreglerat TRPC2 (shTRPC2) m.h.a. shRNA-teknik. Nedreglering av TRPC2 resulterade i stora skillnader i flera viktiga cellul��ra funktioner och i regleringen av sk��ldk��rtelcellernas cellsignalering. Nedreglering av TRPC2 orsakade minskad agonist-beroende frigivning av kalcium fr��n det endoplasmatiska n��tverket, samt minskat agonist-beroende infl��de av extracellul��rt kalcium, men ��kade det basala kalciuminfl��det. Uttrycket av PKCβ1 och PKCδ, SERCA-aktiviteten och kalciumhalten i det endoplasmatiska n��tverket minskade i shTRPC2 celler. Kommunikation mellan kalcium- och cAMP-signalering p��visades vara TRPC2-beroende, vilket visades reglera uttrycket av TSH-receptorn. Vi unders��kte ocks�� betydelsen av TRPC2 kanalen i reglering av sk��ldk��rtelcellers proliferation, migration, vidh��ftning och invasion; processer som alla var d��mpade i shTRPC2 celler. Samamnfattningsvis p��visade dessa resultat en ny och viktig fysiologisk betydelse f��r TRPC2 kanalerna.

An��lise interact��mica da VDAC (voltage-dependent anion selective channel) nos c��rebros aviar, bovino e murino

A VDAC �� a prote��na mais abundante na membrana mitocondrial externa. Exerce o controle da atividade desta organela atrav��s da regula����o da troca de metab��litos e tem fun����o crucial no mecanismo de apoptose. Em nosso caso, os estudos dos complexos prot��icos, das intera����es entre a VDAC e outras prote��nas presentes no interior do neur��nio que auxiliam na manuten����o das fun����es das organelas e da c��lula, fazem parte da chamada interact��mica. O presente estudo determinou o interactoma do complexo prot��ico Hexoquinase-VDAC-ANT presente em c��rebros murino, bovino e aviar. Nosso objetivo foi identificar se as express��es diferenciadas da VDAC1 e VDAC2 verificadas nos c��rebros murino, aviar e bovino, est��o associadas a diferen��as nos interactomas dessas prote��nas. Este estudo revelou que as esp��cies aviar e bovina apresentaram o maior n��mero de complexos prot��icos contendo VDACs (5) quando comparadas com os neur��nios de rato (1), o que �� indicativo de uma cin��tica diferencial de montagem ou desmontagem do complexo. Al��m disso, a VDAC mitocondrial neuronal aviar tamb��m interage com mais prote��nas em rela����o �� VDAC mitocondrial neuronal bovina, o que �� resultado de uma composi����o de subunidades diferenciada. Tais resultados indicam diferen��as significativas quanto ao metabolismo energ��tico e apopt��tico no c��rebro aviar, bovino e murino, existindo intera����es diferenciais da VDAC no c��rebro aviar.

Managing Customer Issues through a Support Channel Network

The importance of after-sales service or service in general can be seen and experienced by customers every day with industrial as well as other non-industrial services or products. This dissertation, drawing on theory and experience, focuses on practical engineering implications, specifically the management of customer issues in the after-sales phase in the mobile phone arena. The main objective of this doctoral dissertation is to investigate customer after-sales issue management, specifically regarding mobile phones. The case studies focus on issue resolution time and the issue of corrective actions. This dissertation consists of a main body and four peer-reviewed journal articles and one manuscript currently under review by a peer-reviewed journal. The main body of this dissertation examines the elements of customer satisfaction, loyalty, and retention with respect to corrective actions to address customer issues and issue resolution time through literature and empirical studies. The five independent works are case studies supporting the thesis research questions. This study examines four questions: 1) What are the factors affecting corrective actions for customers? 2) How can customer issue resolution time be controlled? 3) What are the factors affecting processes in the service chain? and 4) How can communication be measured in a service chain? In this work, both quantitative and qualitative analysis methods are used. The main body of the thesis reviews the literature regarding the elements that bridge the five case studies. The case studies of the articles and surveys lean more toward the methodology of critical positivism and then apply the interpretive approach in interpreting the results. The case study articles employ various statistical methods to analyze and to interpret the empirical and survey data. The statistical methods were used to create a model that is useful for significantly optimizing issue resolution time. Moreover, it was found that samples for verifying issues provided by the customer neither improve the perceived quality of corrective actions nor the perceived quality of issue resolution time. The term ���service��� in this work is limited to the technical services that are provided by product manufacturers and after-sales authorized service vendors. On the basis of this research work, it has been observed that corrective actions and issue resolution time are associated with customer satisfaction and hence, according to induction theory, to customer loyalty and retention. This thesis utilizes knowledge of marketing and customer relationships to contribute to the existing body of knowledge concerning information and communication technology for after-sales service recovery of mobile terminals. The established models in the thesis contribute to the existing knowledge of the after-sales process of dealing with customer issues in the field of mobile phones. The findings suggest that process managers could focus more on communication and training provided to the staff as new technology evolves rapidly. The study also suggest the managers formulate strategies for how customers can be kept informed on a regular basis of the status of issues that have been escalated for corrective action. The findings also lay the foundation for the comprehensive objective to control the entire product development process, starting with conceptualization. This implies that robust design should be applied to the new products so that problems affecting customer service quality are not repeated. The objective will be achieved when the entire service chain from product development to the final user can be modeled and this model can be used to support the organization at all levels.

Distribution channel plan for wound care products: Case 3M Finland Ltd.

The aim of this master���s thesis was to make a qualitative marketing research and on the basis of this to develop a distribution plan for the case company Finnish 3M Ltd.���s wound care products. The literature review includes three important parts: distribution channel planning, the buying behavior of seniors, and special characteristics of health care products��� marketing. The empirical part of this thesis comprises two different parts. The first part is a marketing research, in which the buying behavior of wound care products is studied in Espoo. The research aim was to examine, in which distribution channels the wound care patients under home care would most preferably buy wound care products during the time period, when municipalities will not yet provide the products for free. The data was collected through semi-structured phone interviews and regular interviews, and was treated qualitatively and anonymously. The study revealed that the recommendations of nurses and doctors influenced most the buying behavior of wound care customers. In the second part of the thesis a distribution channel plan for wound care products was made for the case company 3M Finland Ltd. based on the results. 3M Finland Ltd. should focus on pharmacies, online-stores and municipal health centers as their main distributors.

Vasorelaxant effects of the potassium channel opener SR 47063 on the isolated human saphenous vein and rat aorta

The vasorelaxant effects of SR 47063 (4-(2-cyanimino-1,2-dihydropyrid-1-yl)-2,2-dimethyl-6-nitrochromene), a new K+-channel opener structurally related to levcromakalim, were examined in isolated human saphenous vein (HSV) and rat aorta (RA). HSV or RA rings were precontracted with either KCl or noradrenaline and cumulative relaxant concentration-response curves were obtained for SR 47063 (0.1 nM to 1 ��M) in the presence or absence of 3 ��M glibenclamide. SR 47063 potently relaxed HSV and RA precontracted with 20 mM (but not 60 mM) KCl or 10 ��M noradrenaline in a concentration-dependent manner, showing slightly greater activity in the aorta. The potency of the effect of SR 47063 on HSV and RA was 12- and 58-fold greater, respectively, than that reported for the structurally related K+-channel opener levcromakalim. The vasorelaxant action of SR 47063 in both blood vessels was strongly inhibited by 3 ��M glibenclamide, consistent with a mechanism of action involving ATP-dependent K+-channels.

ClC-5 chloride channel and kidney stones: what is the link?

Nephrolithiasis is one of the most common diseases in the Western world. The disease manifests itself with intensive pain, sporadic infections, and, sometimes, renal failure. The symptoms are due to the appearance of urinary stones (calculi) which are formed mainly by calcium salts. These calcium salts precipitate in the renal papillae and/or within the collecting ducts. Inherited forms of nephrolithiasis related to chromosome X (X-linked hypercalciuric nephrolithiasis or XLN) have been recently described. Hypercalciuria, nephrocalcinosis, and male predominance are the major characteristics of these diseases. The gene responsible for the XLN forms of kidney stones was cloned and characterized as a chloride channel called ClC-5. The ClC-5 chloride channel belongs to a superfamily of voltage-gated chloride channels, whose physiological roles are not completely understood. The objective of the present review is to identify recent advances in the molecular pathology of nephrolithiasis, with emphasis on XLN. We also try to establish a link between a chloride channel like ClC-5, hypercalciuria, failure in urine acidification and protein endocytosis, which could explain the symptoms exhibited by XLN patients.

An acid-sensing ion channel that detects ischemic pain

Ischemic pain occurs when there is insufficient blood flow for the metabolic needs of an organ. The pain of a heart attack is the prototypical example. Multiple compounds released from ischemic muscle likely contribute to this pain by acting on sensory neurons that innervate muscle. One such compound is lactic acid. Here, we show that ASIC3 (acid-sensing ion channel #3) has the appropriate expression pattern and physical properties to be the detector of this lactic acid. In rats, it is expressed only in sensory neurons and then only on a minority (~40%) of these. Nevertheless, it is expressed at extremely high levels on virtually all dorsal root ganglion sensory neurons that innervate the heart. It is extraordinarily sensitive to protons (Hill slope 4, half-activating pH 6.7), allowing it to readily respond to the small changes in extracellular pH (from 7.4 to 7.0) that occur during muscle ischemia. Moreover, both extracellular lactate and extracellular ATP increase the sensitivity of ASIC3 to protons. This final property makes ASIC3 a "coincidence detector" of three molecules that appear during ischemia, thereby allowing it to better detect acidosis caused by ischemia than other forms of systemic acidosis such as hypercapnia.

Down-regulation of the cardiac sarcoplasmic reticulum ryanodine channel in severely food-restricted rats

We have shown that myocardial dysfunction induced by food restriction is related to calcium handling. Although cardiac function is depressed in food-restricted animals, there is limited information about the molecular mechanisms that lead to this abnormality. The present study evaluated the effects of food restriction on calcium cycling, focusing on sarcoplasmic Ca2+-ATPase (SERCA2), phospholamban (PLB), and ryanodine channel (RYR2) mRNA expressions in rat myocardium. Male Wistar-Kyoto rats, 60 days old, were submitted to ad libitum feeding (control rats) or 50% diet restriction for 90 days. The levels of left ventricle SERCA2, PLB, and RYR2 were measured using semi-quantitative RT-PCR. Body and ventricular weights were reduced in 50% food-restricted animals. RYR2 mRNA was significantly decreased in the left ventricle of the food-restricted group (control = 5.92 �� 0.48 vs food-restricted group = 4.84 �� 0.33, P < 0.01). The levels of SERCA2 and PLB mRNA were similar between groups (control = 8.38 �� 0.44 vs food-restricted group = 7.96 �� 0.45, and control = 1.52 �� 0.06 vs food-restricted group = 1.53 �� 0.10, respectively). Down-regulation of RYR2 mRNA expressions suggests that chronic food restriction promotes abnormalities in sarcoplasmic reticulum Ca2+ release.