260 research outputs found

    The effect of sodium valproate in Cushing's disease, Nelson's syndrome and Addison's disease

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    We investigated the effect of sodium valproate on plasma ACTH and serum cortisol concentrations in different pathological states of ACTH hypersecretion. Five patients with pituitary dependent Cushing's syndrome, two patients with Nelson's syndrome and five patients with Addison's disease were studied. Neither a single dose nor long term administration of sodium valproate resulted in a significant decrease of plasma ACTH levels in patients with Cushing's disease and Nelson's syndrome. Furthermore, the response of ACTH and cortisol to stimulation with lysine-vasopressin was unaffected during acute and chronic treatment. Patients with Addison's disease showed a slight attenuation of the ACTH response to lysine-vasopressin as compared to placebo but the difference was not statistically significant. In conclusion: sodium valproate does not appear to be effective in controlling ACTH hypersecretion in pituitary dependent Cushing's syndrome

    Nonhypnotic low-dose etomidate for rapid correction of hypercortisolaemia in cushing's syndrome

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    We determined the adrenostatic potential of low-dose nonhypnotic etomidate in six patients with Cushing's syndrome (ectopic Cushing's syndrome,n=2; Cushing's disease,n=3; bilateral adrenal adenoma,n=1). Etomidate was given as a continuous infusion for 32 h in a dose of 2.5 mg/h (n=5) or 0.3 mg/kg/h (n=3), respectively. Saline was given during a control period. The responsiveness to exogenous ACTH was studied during placebo and 7 and 31 h after commencing etomidate by administration of 250 µg 1–24 ACTH i.v. Etomidate (2.5 mg/h) led to a consistent decrease in serum cortisol in all patients from a mean of 39.4±13.3 to 21.1±5.7 µg/dl after 7 h (P<0.05 compared with placebo). After 24 h cortisol was reduced further to a mean steady state concentration of 12.3±5.7 µg/dl (P<0.05). At the end of the infusion period the cortisol increase in response to ACTH was reduced but not abolished. In contrast, a dose of 0.3 mg/kg/h etomidate induced unresponsiveness of serum cortisol to exogenous ACTH within 7 h. However, sedation was observed in two out of three patients at this dose, while during etomidate in a dose of 2.5 mg/h no side effects were seen. We conclude that low-dose non-hypnotic etomidate reduces serum cortisol to within the normal range in patients with Cushing's syndrome. The possibility to dissociate the adrenostatic effect of etomidate from its hypnotic action, the absence of side effects, and the i.v. route suggest that etomidate in a dose of 0.04–0.05 mg/kg/h may become the drug of choice for rapid initial control of hypercortisolism

    Clonal Composition of Human Adrenocortical Neoplasms

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    The mechanisms of tumorigenesis of adrenocortical neoplasms are still not understood. Tumor formation may be the result of spontaneous transformation of adrenocortical cells by somatic mutations. Another factor stimulating adrenocortical cell growth and potentially associated with formation of adrenal adenomas and, less frequently, carcinomas is the chronic elevation of proopiomelanocortin-derived peptides in diseases like ACTH-dependent Cushing's syndrome and congenital adrenal hyperplasia. To further investigate the pathogenesis of adrenocortical neoplasms, we studied the clonal composition of such tumors using X-chromosome inactivation analysis of the highly polymorphic region Xcen-Xp11.4 with the hybridization probe M27ß, which maps to a variable number of tandem repeats on the X-chromsome. In addition, polymerase chain reaction amplification of a phosphoglycerokinase gene polymorphism was performed. After DNA extraction from tumorous adrenal tissue and normal leukocytes in parallel, the active X-chromosome of each sample was digested with the methylation-sensitive restriction enzyme HpaII. A second digestion with an appropriate restriction enzyme revealed the polymorphism of the region Xcen-Xp11.4 and the phosphoglycerokinase locus. Whereas in normal polyclonal tissue both the paternal and maternal alleles are detected, a monoclonal tumor shows only one of the parental alleles. A total of 21 female patients with adrenal lesions were analyzed; 17 turned out to be heterozygous for at least one of the loci. Our results were as follows: diffuse (n = 4) and nodular (n = 1) adrenal hyperplasia in patients with ACTH-dependent Cushing's syndrome, polyclonal pattern; adrenocortical adenomas (n = 8), monoclonal (n = 7), as well as polyclonal (n = 1); adrenal carcinomas (n = 3), monoclonal pattern. One metastasis of an adrenocortical carcinoma showed a pattern most likely due to tumor-associated loss of methylation. In the special case of a patient with bilateral ACTH-independent macronodular hyperplasia, diffuse hyperplastic areas and a small nodule showed a polyclonal pattern, whereas a large nodule was monoclonal. We conclude that most adrenal adenomas and carcinomas are monoclonal, whereas diffuse and nodular adrenal hyperplasias are polyclonal. The clonal composition of ACTH-independent massive macronodular hyperplasia seems to be heterogeneous, consisting of polyclonal and monoclonal areas

    A review on challenges of autonomous mobile robot and sensor fusion methods

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    Autonomous mobile robots are becoming more prominent in recent time because of their relevance and applications to the world today. Their ability to navigate in an environment without a need for physical or electro-mechanical guidance devices has made it more promising and useful. The use of autonomous mobile robots is emerging in different sectors such as companies, industries, hospital, institutions, agriculture and homes to improve services and daily activities. Due to technology advancement, the demand for mobile robot has increased due to the task they perform and services they render such as carrying heavy objects, monitoring, search and rescue missions, etc. Various studies have been carried out by researchers on the importance of mobile robot, its applications and challenges. This survey paper unravels the current literatures, the challenges mobile robot is being faced with. A comprehensive study on devices/sensors and prevalent sensor fusion techniques developed for tackling issues like localization, estimation and navigation in mobile robot are presented as well in which they are organised according to relevance, strengths and weaknesses. The study therefore gives good direction for further investigation on developing methods to deal with the discrepancies faced with autonomous mobile robot.http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=6287639pm2021Electrical, Electronic and Computer Engineerin

    Adrenostatische Therapie mit Metyrapon und Aminoglutethimid beim ACTH-abhängigen Cushing-Syndrom

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    Bei zehn Patienten mit ACTH-abhängigem Cushing-Syndrom, vier mit ektopem Cushing-Syndrom und sechs mit M. Cushing, wurde retrospektiv die Wirksamkeit einer adrenostatischen Therapie mit Metyrapon (Metopiron®) und Aminoglutethimid (Orimeten®) untersucht. Unter Metyrapon allein (n = 5) sowie in Kombination mit Aminoglutethimid (n = 5) kam es bei allen Patienten zu einer dauerhaften Senkung der Serum-Cortisol-Konzentration. Die Beobachtungszeit betrug 2 Wochen bis 4 Jahre. Der angestrebte therapeutische Bereich von < 16 µg/dl wurde bei sieben Patienten erreicht. Im Verlauf der Therapie wurde ein Anstieg der mittleren Plasma-ACTH-Konzentration beobachtet; dabei kam es nicht zu einem »Escape« der Cortisol-Konzentration. Eine Einschränkung erfuhr die adrenostatische Therapie allein durch die Nebenwirkungen, die bei zwei Patienten zu einer Beendigung der Therapie führten. Folgerung: Die adrenostatische Therapie mit Metyrapon und Aminoglutethimid ist wirksam und praktikabel. Sie eignet sich nicht nur zur akuten Behandlung des floriden Cushing-Syndroms, sondern auch zur Langzeittherapie, wenn eine kurative Therapie nicht möglich ist.The adrenostatic effect of metyrapone (Metopiron®) and aminoglutethimide (Orimeten®) was assessed retrospectively in ten patients with ACTH-dependent Cushing's syndrome, four of them with the ectopic form. Five patients received metyrapone only, the other five both metyrapone and aminoglutethimide. Persistent lowering of the serum cortisol level was achieved in all, after an observation period of two weeks to four years. The intended therapeutic level of below 16 µg/100 ml was achieved in seven patients. In the course of treatment there was a rise in mean plasma ACTH concentration, but without an »escape« phenomenon. The adrenostatic treatment had to be limited, if at all, only because of side effects, which in two patients required that the drug administration be terminated. It is concluded that adrenostatic treatment with metyrapone and aminoglutethimide is effective and practical. It is suitable not only in the management of florid Cushing's syndrome, but also for long-term treatment when complete cure is not possible

    Behandlung des metastasierten Nebennierenkarzinoms mit Suramin

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    Bei einem 45jährigen Patienten wurde im April 1986 ein rechtsseitiges Nebennierenrindenkarzinom (978 g) entfernt und das Tumorbett postoperativ mit 40 Gy bestrahlt. Wegen multipler Lungenmetastasen wurde im Januar und im Juni 1987 eine Polychemotherapie mit Cisplatin, Etoposid und Bleomycin durchgeführt, ohne daß eine Befundbesserung erreicht wurde. Auch eine Therapie mit Mitotan (Lysodren®) blieb wirkungslos und mußte wegen schwerer Nebenwirkungen beendet werden. Im August 1987 wurde eine Therapie mit Suramin (Germanin®) begonnen. Nach einer Aufsättigungsdosis von 10,7 g über 6 Wochen kam es zu einer nahezu vollständigen Rückbildung der Lungenmetastasen. Während einer niedrig dosierten Erhaltungstherapie mit Suramin wurden im Januar 1988 erneut Lungenmetastasen nachweisbar. Eine Dosissteigerung führte zu Wachstumsstillstand, nicht jedoch zur Rückbildung der Metastasen. Der Patient starb im April 1988 überraschend an akutem Kreislaufversagen. Die Suramin-Therapie war 6 Wochen zuvor bei Bronchopneumonie und verschlechtertem Allgemeinzustand beendet worden. Nebenwirkungen der Suramin-Therapie waren Thrombozytopenie, Gerinnungsstörungen und eine mäßiggradige Proteinurie

    Diagnostik und Therapie asymptomatischer Nebennierentumoren

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    Bei 23 Frauen und neun Männern im mittleren Alter von 54 (25-73) Jahren wurde bei der Klärung anderer Beschwerden zufällig ein asymptomatischer Nebennierentumor entdeckt. In allen Fällen ließen sich die Tumoren computertomographisch darstellen. Achtmal waren sie beidseits lokalisiert, in je 12 Fällen rechts- oder linksseitig. Der durchschnittliche Tumordurchmesser betrug 3 (1-9) cm. Vier Tumoren (12,5 %) wiesen eine endokrine Aktivität auf (ein Phäochromozytom, drei cortisolproduzierende Tumoren). Acht Patienten wurden adrenalektomiert, dabei ergaben sich sechs Nebennierenadenome, ein benignes Phäochromozytom und ein Ganglioneurom. Eine Feinnadelbiopsie wurde bei zwei Patienten vorgenommen, der zytologische Befund war benigne. Computertomographische Verlaufskontrollen bei elf (34,4 %) der nicht-operierten Patienten 6-48 Monate (im Mittel 14 Monate) später zeigten bei keinem der Patienten eine Größenzunahme des Tumors. Daher erscheint es bei zufällig diagnostizierten Nebennierentumoren gerechtfertigt, zunächst einmal den Verlauf zu beobachten, da gutartige Prozesse offensichtlich weitaus häufiger sind als maligne. Bei einem Tumordurchmesser von mehr als 6 cm ist jedoch wegen des Malignitätsrisikos eine Adrenalektomie durchzuführen

    The Bits of Silence : Redundant Traffic in VoIP

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    Human conversation is characterized by brief pauses and so-called turn-taking behavior between the speakers. In the context of VoIP, this means that there are frequent periods where the microphone captures only background noise – or even silence whenever the microphone is muted. The bits transmitted from such silence periods introduce overhead in terms of data usage, energy consumption, and network infrastructure costs. In this paper, we contribute by shedding light on these costs for VoIP applications. We systematically measure the performance of six popular mobile VoIP applications with controlled human conversation and acoustic setup. Our analysis demonstrates that significant savings can indeed be achievable - with the best performing silence suppression technique being effective on 75% of silent pauses in the conversation in a quiet place. This results in 2-5 times data savings, and 50-90% lower energy consumption compared to the next better alternative. Even then, the effectiveness of silence suppression can be sensitive to the amount of background noise, underlying speech codec, and the device being used. The codec characteristics and performance do not depend on the network type. However, silence suppression makes VoIP traffic network friendly as much as VoLTE traffic. Our results provide new insights into VoIP performance and offer a motivation for further enhancements, such as performance-aware codec selection, that can significantly benefit a wide variety of voice assisted applications, as such intelligent home assistants and other speech codec enabled IoT devices.Peer reviewe

    Comparing nuclear power trajectories in Germany and the UK: from ‘regimes' to ‘democracies’ in sociotechnical transitions and Discontinuities

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    This paper focuses on arguably the single most striking contrast in contemporary major energy politics in Europe (and even the developed world as a whole): the starkly differing civil nuclear policies of Germany and the UK. Germany is seeking entirely to phase out nuclear power by 2022. Yet the UK advocates a ‘nuclear renaissance’, promoting the most ambitious new nuclear construction programme in Western Europe.Here,this paper poses a simple yet quite fundamental question: what are the particular divergent conditions most strongly implicated in the contrasting developments in these two countries. With nuclear playing such an iconic role in historical discussions over technological continuity and transformation, answering this may assist in wider understandings of sociotechnical incumbency and discontinuity in the burgeoning field of‘sustainability transitions’. To this end, an ‘abductive’ approach is taken: deploying nine potentially relevant criteria for understanding the different directions pursued in Germany and the UK. Together constituted by 30 parameters spanning literatures related to socio-technical regimes in general as well as nuclear technology in particular, the criteria are divided into those that are ‘internal’ and ‘external’ to the ‘focal regime configuration’ of nuclear power and associated ‘challenger technologies’ like renewables. It is ‘internal’ criteria that are emphasised in conventional sociotechnical regime theory, with ‘external’ criteria relatively less well explored. Asking under each criterion whether attempted discontinuation of nuclear power would be more likely in Germany or the UK, a clear picture emerges. ‘Internal’ criteria suggest attempted nuclear discontinuation should be more likely in the UK than in Germany– the reverse of what is occurring. ‘External’ criteria are more aligned with observed dynamics –especially those relating to military nuclear commitments and broader ‘qualities of democracy’. Despite many differences of framing concerning exactly what constitutes ‘democracy’, a rich political science literature on this point is unanimous in characterising Germany more positively than the UK. Although based only on a single case,a potentially important question is nonetheless raised as to whether sociotechnical regime theory might usefully give greater attention to the general importance of various aspects of democracy in constituting conditions for significant technological discontinuities and transformations. If so, the policy implications are significant. A number of important areas are identified for future research, including the roles of diverse understandings and specific aspects of democracy and the particular relevance of military nuclear commitments– whose under-discussion in civil nuclear policy literatures raises its own questions of democratic accountability
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