923 resultados para Positive definite kernels and functions


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OBJECTIVE: A novel biphasic calcium phosphate (CaP) granulate consisting of hydroxyapatite (HA) and beta-tricalciumphosphate (TCP) was compared with pure HA and pure TCP and with autograft as positive control. MATERIALS AND METHODS: Four standardized bone defects were prepared in both mandibular angles of 16 minipigs and grafted with autogenous bone chips, HA, HA/TCP (60% : 40%), or TCP. Histologic and histomorphometric analysis of bone formation and graft degradation followed healing periods of 2, 4, 8, and 24 weeks. RESULTS: 2 weeks: more bone formation in defects filled with autograft than with the three CaP materials (P<0.05). 4 weeks: bone formation differed significantly (P<0.05) between all four materials (autograft>TCP>HA/TCP>HA). 8 weeks: more bone formation in defects with autograft and TCP than with HA/TCP (P<0.05), and HA/TCP had more bone formation than HA (P<0.05). 24 weeks: no difference in bone formation between the groups. Autograft and TCP resorbed quickly and almost completely over 8 weeks, whereas HA/TCP and HA showed limited degradation over 24 weeks. CONCLUSION: All defects healed with mature lamellar bone and intimate contact between bone and the remaining graft material. The rate of bone formation corresponded to the content of TCP in the CaP materials.

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Interleukin-1 beta is a potent mediator of the acute-phase response. However, the effects of interleukin-1 beta administration on the topic in vivo production of acute-phase proteins and albumin are so far not well understood. Overnight fasted rats were subcutaneously injected with 0.2 mL 0.9% NaCl (control group) or 6.25 micrograms recombinant human interleukin-1 beta, and rectal temperature was measured at intervals up to 48 h. Livers were perfused-fixed in vivo prior to injection (base-line), and at 9, 24, and 48 h following the interleukin-1 beta injection. Fibrinogen, orosomucoid (alpha 1-acid glycoprotein) and albumin were immunostained using a streptavidin-biotin-immunoperoxidase technique. Rectal temperature peaked 5 h after the single interleukin-1 beta injection, and fell gradually to base-line values by 24 h. Prior to injection only a few hepatocytes, randomly scattered throughout the liver lobule, stained positive for fibrinogen and orosomucoid. In contrast, all hepatocytes stained uniformly positive for fibrinogen and orosomucoid 9 h after interleukin-1 beta injection, whereas at 24 h a predominant centrilobular staining pattern occurred. Due to fasting, albumin positive hepatocytes were already reduced at base-line in both groups. Interleukin-1 beta induced a further significant loss of albumin positive cells in the periportal zone (35 +/- 21%) at 9 h when compared with controls (58 +/- 11%, p = 0.037). In conclusion, subcutaneous interleukin-1 beta (probably by stimulation of interleukin-6) strongly induces fibrinogen and orosomucoid expression in rat liver, and suppresses immunohistochemically stainable albumin in a heterogenous way, mainly in the periportal zone.

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Comments on an article by Kashima et al. (see record 2007-10111-001). In their target article Kashima and colleagues try to show how a connectionist model conceptualization of the self is best suited to capture the self's temporal and socio-culturally contextualized nature. They propose a new model and to support this model, the authors conduct computer simulations of psychological phenomena whose importance for the self has long been clear, even if not formally modeled, such as imitation, and learning of sequence and narrative. As explicated when we advocated connectionist models as a metaphor for self in Mischel and Morf (2003), we fully endorse the utility of such a metaphor, as these models have some of the processing characteristics necessary for capturing key aspects and functions of a dynamic cognitive-affective self-system. As elaborated in that chapter, we see as their principal strength that connectionist models can take account of multiple simultaneous processes without invoking a single central control. All outputs reflect a distributed pattern of activation across a large number of simple processing units, the nature of which depends on (and changes with) the connection weights between the links and the satisfaction of mutual constraints across these links (Rummelhart & McClelland, 1986). This allows a simple account for why certain input features will at times predominate, while others take over on other occasions. (PsycINFO Database Record (c) 2008 APA, all rights reserved)

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Background The main objective of this study was to assess and compare patient satisfaction with Neural Therapy (NT) and conventional medicine (COM) in primary care for musculoskeletal diseases. Methods A cross-sectional study in primary care for musculoskeletal disorders covering 77 conventional primary care providers and 18 physicians certified in NT with 241 and 164 patients respectively. Patients and physicians documented consultations and patients completed questionnaires at a one-month follow-up. Physicians documented duration and severity of symptoms, diagnosis, and procedures. The main outcomes in the evaluation of patients were: fulfillment of expectations, perceived treatment effects, and patient satisfaction. Results The most frequent diagnoses belonged to the group of dorsopathies (39% in COM, 46% in NT). We found significant differences between NT and COM with regard to patient evaluations. NT patients documented better fulfilment of treatment expectations and higher overall treatment satisfaction. More patients in NT reported positive side effects and less frequent negative effects than patients in COM. Also, significant differences between NT and COM patients were seen in the quality of the patient-physician interaction (relation and communication, medical care, information and support, continuity and cooperation, facilities availability, and accessibility), where NT patients showed higher satisfaction. Differences were also found with regard to the physicians' management of disease, with fewer work incapacity attestations issued and longer consultation times in NT. Conclusion Our findings show a significantly higher treatment and care-related patient satisfaction with primary care for musculoskeletal diseases provided by physicians practising Neural Therapy.

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BACKGROUND: Although urinalysis is simple and inexpensive to perform, the finding of microhaematuria on urinalysis may be unreliable for diagnosing urolithiasis. OBJECTIVE: To evaluate microhaematuria as a diagnostic marker for urolithiasis compared with low-dose unenhanced multidetector computed tomography (MDCT) as the "gold standard". SETTING: A level 1 emergency department in a tertiary referral university teaching hospital. DESIGN: Retrospective analysis. METHODS: A study was undertaken to assess whether the finding of microhaematuria was diagnostic for urolithiasis using a low-dose unenhanced MDCT-based diagnosis as the reference standard by reviewing the records of all patients who presented to the emergency department with colicky flank pain and underwent a CT scan between January 2003 and December 2005. RESULTS: Urolithiasis was present (as defined by low-dose unenhanced MDCT) in 507/638 patients (79%); 341/638 (53%) were true positive for urolithiasis, 76 (12%) were true negative, 55 (9%) were false positive and 166 (26%) were false negative. Microhaematuria as a test for urolithiasis in patients presenting to the emergency department therefore has a sensitivity, specificity, positive predictive value and negative predictive value of 67%, 58%, 86% and 31%, respectively. 58% of the urinalysis results were negative for haematuria in the subset of patients with significant alternative diagnoses. CONCLUSIONS: The sensitivity, specificity and negative predictive value of microhaematuria on urinalysis for urolithiasis using unenhanced MDCT as the reference standard were low. This suggests that, when urolithiasis is clinically suspected, unenhanced MDCT is indicated without urinalysis being a prerequisite.

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The developmental processes and functions of an organism are controlled by the genes and the proteins that are derived from these genes. The identification of key genes and the reconstruction of gene networks can provide a model to help us understand the regulatory mechanisms for the initiation and progression of biological processes or functional abnormalities (e.g. diseases) in living organisms. In this dissertation, I have developed statistical methods to identify the genes and transcription factors (TFs) involved in biological processes, constructed their regulatory networks, and also evaluated some existing association methods to find robust methods for coexpression analyses. Two kinds of data sets were used for this work: genotype data and gene expression microarray data. On the basis of these data sets, this dissertation has two major parts, together forming six chapters. The first part deals with developing association methods for rare variants using genotype data (chapter 4 and 5). The second part deals with developing and/or evaluating statistical methods to identify genes and TFs involved in biological processes, and construction of their regulatory networks using gene expression data (chapter 2, 3, and 6). For the first part, I have developed two methods to find the groupwise association of rare variants with given diseases or traits. The first method is based on kernel machine learning and can be applied to both quantitative as well as qualitative traits. Simulation results showed that the proposed method has improved power over the existing weighted sum method (WS) in most settings. The second method uses multiple phenotypes to select a few top significant genes. It then finds the association of each gene with each phenotype while controlling the population stratification by adjusting the data for ancestry using principal components. This method was applied to GAW 17 data and was able to find several disease risk genes. For the second part, I have worked on three problems. First problem involved evaluation of eight gene association methods. A very comprehensive comparison of these methods with further analysis clearly demonstrates the distinct and common performance of these eight gene association methods. For the second problem, an algorithm named the bottom-up graphical Gaussian model was developed to identify the TFs that regulate pathway genes and reconstruct their hierarchical regulatory networks. This algorithm has produced very significant results and it is the first report to produce such hierarchical networks for these pathways. The third problem dealt with developing another algorithm called the top-down graphical Gaussian model that identifies the network governed by a specific TF. The network produced by the algorithm is proven to be of very high accuracy.

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Distinct potassium, anion, and calcium channels in the plasma membrane and vacuolar membrane of plant cells have been identified and characterized by patch clamping. Primarily owing to advances in Arabidopsis genetics and genomics, and yeast functional complementation, many of the corresponding genes have been identified. Recent advances in our understanding of ion channel genes that mediate signal transduction and ion transport are discussed here. Some plant ion channels, for example, ALMT and SLAC anion channel subunits, are unique. The majority of plant ion channel families exhibit homology to animal genes; such families include both hyperpolarization- and depolarization-activated Shaker-type potassium channels, CLC chloride transporters/channels, cyclic nucleotide-gated channels, and ionotropic glutamate receptor homologs. These plant ion channels offer unique opportunities to analyze the structural mechanisms and functions of ion channels. Here we review gene families of selected plant ion channel classes and discuss unique structure-function aspects and their physiological roles in plant cell signaling and transport.

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In a recent policy document of the organized employers in the care and welfare sector in The Netherlands (the MO Group), directors and board members of care and welfare institutions present themselves as "social entrepreneurs", managing their institutions as look-a like commercial companies. They are hardly criticized and there is not any countervailing power of significance. The workers are focusing on their own specialized professional fields and divided as a whole. Many government officials are in favour or do not bother. The relatively small number of intellectual workers in Dutch care and welfare are fragmented and pragmatic. From a democratic point of view this is a worrying situation. From a professional point of view the purpose and functions of professional care and welfare work are at stake. The penetration of market mechanisms and the take-over by commercially orientated managers result from unquestioned adaptation of Anglo-Saxon policy in The Netherlands in the 1990's, following the crisis of the Welfare State in the late 1980's. The polder country is now confronted fully with the pressure and negative effects of unbalanced powers in the institutions, i.e. Managerialism. After years of silence, the two principal authentic critics of Dutch care and welfare, Harry Kunneman and Andries Baart, are no longer voices crying in the wilderness, but are getting a response from a growing number of worried workers and intellectuals. Kunneman and Baart warn against the restriction of professional space and the loss of normative values and standards in the profession. They are right. It is high time to make room for criticism and to start a debate about the future of the social professions in The Netherlands, better: in Europe. Research, discussion and action have to prove how worrying the everyday situation of professional workers is, what goals have to be set and what strategy to be chosen.

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We explored and refined the hypothesis that during a first episode of acute schizophrenia a disorganization of brain functioning is present. A novel EEG measure was introduced, Global Field Synchronization (GFS), that estimates functional connectivity of brain processes in different EEG frequency bands. The measure was applied to EEG's from 11 never-treated, first-episode, young patients with an acute, positive, schizophrenic symptomatology and from 19 controls, residing in Bern, Switzerland. In comparison to age- and sex- matched controls, patients had significantly decreased GFS in the theta EEG frequency band, indicating a loosened functional connectivity of processes in this frequency. The result was confirmed in an independent, comparable patient group from Osaka, Japan (9 patients and 9 controls), thus making a total of 20 analyzed patients. Previous EEG research in healthy, awake subjects indicated a positive correlation of theta activity with memory functions. Thus, our result suggests a loss of mutual interdependence of memory functions in patients with acute schizophrenia, which agrees well with previous reports of working memory dysfunction in schizophrenia.

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OBJECTIVES To review the incidence, clinical presentation, definite management and 1-year outcome in patients with aorto-oesophageal fistulation (AOF) following thoracic endovascular aortic repair (TEVAR). METHODS International multicentre registry (European Registry of Endovascular Aortic Repair Complications) between 2001 and 2011 with a total caseload of 2387 TEVAR procedures (17 centres). RESULTS Thirty-six patients with a median age of 69 years (IQR 56-75), 25% females and 9 patients (19%) following previous aortic surgery were identified. The incidence of AOF in the entire cohort after TEVAR in the study period was 1.5%. The primary underlying aortic pathology for TEVAR was atherosclerotic aneurysm formation in 53% of patients and the median time to development of AOF was 90 days (IQR 30-150). Leading clinical symptoms were fever of unknown origin in 29 (81%), haematemesis in 19 (53%) and shock in 8 (22%) patients. Diagnosis could be confirmed via computed tomography in 92% of the cases with the leading sign of a new mediastinal mass in 28 (78%) patients. A conservative approach resulted in a 100% 1-year mortality, and 1-year survival for an oesophageal stenting-only approach was 17%. Survival after isolated oesophagectomy was 43%. The highest 1-year survival rate (46%) could be achieved via an aggressive treatment including radical oesophagectomy and aortic replacement [relative risk increase 1.73 95% confidence interval (CI) 1.03-2.92]. The survival advantage of this aggressive treatment modality could be confirmed in bootstrap analysis (95% CI 1.11-3.33). CONCLUSIONS The development of AOF is a rare but lethal complication after TEVAR, being associated with the need for emergency TEVAR as well as mediastinal haematoma formation. The only durable and successful approach to cure the disease is radical oesophagectomy and extensive aortic reconstruction. These findings may serve as a decision-making tool for physicians treating these complex patients.

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Elevation of ketone bodies in dairy cows frequently occurs in early lactation, usually concomitantly with a lack of energy and glucose. The objective of this study was to induce an elevated plasma β-hydroxybutyrate (BHBA) concentration over 48 h in mid-lactating dairy cows (i.e., during a period of positive energy balance and normal glucose plasma concentrations). Effects of BHBA infusion on feed intake, metabolism, and performance were investigated. Thirteen cows were randomly assigned to 1 of 2 infusion groups, including an intravenous infusion with Na-dl-β-OH-butyrate (1.7 mol/L) to achieve a plasma concentration of 1.5 to 2.0 mmol/L of BHBA (HyperB; n=5), or an infusion of 0.9% saline solution (control; n=8). Blood was sampled before and hourly during the 48 h of infusion. In the liver, mRNA transcripts related to gluconeogenesis (pyruvate carboxylase, glucose 6-phosphatase, mitochondrial phosphoenolpyruvate carboxykinase), phosphofructokinase, pyruvate dehydrogenase complex, and fatty acid synthesis (acetyl-coenzyme A carboxylase, fatty acid synthase) were measured by real-time PCR. Glyceraldehyde-3-phosphate dehydrogenase and ubiquitin were used as housekeeping genes. Changes (difference between before and after 48-h infusion) during the infusion period were evaluated by ANOVA with treatment as fixed effect, and area under the curve of variables was calculated on the second day of experiment. The plasma BHBA concentration in HyperB cows was 1.74 ± 0.02 mmol/L (mean ± SE) compared with 0.59 ± 0.02 mmol/L for control cows. The change in feed intake, milk yield, and energy corrected milk did not differ between the 2 experimental groups. Infusion of BHBA reduced the plasma glucose concentration (3.47 ± 0.11 mmol/L) in HyperB compared with control cows (4.11 ± 0.08 mmol/L). Plasma glucagon concentration in HyperB was lower than the control group. All other variables measured in plasma were not affected by treatment. In the liver, changes in mRNA abundance for the selected genes were similar between 2 groups. Results demonstrate that intravenous infusion of BHBA decreased plasma glucose concentration in dairy cows, but this decrease could not be explained by alterations in insulin concentrations or key enzymes related to gluconeogenesis. Declined glucose concentration is likely functionally related to decreased plasma glucagon concentration.

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This study reports the implementation of a Training of Intercultural Competence and Tolerance (TICT) for upper-secondary school students and the empirical evaluation of its effectiveness. The TICT program was developed to counteract increasing interethnic conflicts in the North Caucasus Federal District of Russia. It is based on the theoretical and empirical framework of social psychology and cross-cultural psychology. The training effectiveness was assessed by conducting pre- and post-surveys among the training participants. The results indicate that TICT contributes to the development of a positive ethnic identity and the formation of a civic identity among the participating youth. It also increases their optimism regarding the future of interethnic relations in Russia and the subjective level of intercultural competence of majority group youth towards minority cultures. Thus, the evaluation of the training effectiveness of the TICT has shown that the aims of the training have been achieved to a large extent and that the Training of Intercultural Competence and Tolerance can be effectively used to prevent interethnic conflicts and promote interethnic relations in multicultural schools. Suggestions for the practical implementation of the TICT as well as for future research on the training's effectiveness are discussed.

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In addition to self reports and questionnaires, biomarkers are of relevance in the diagnosis of and therapy for alcohol use disorders. Traditional biomarkers such as gamma-glutamyl transpeptidase or mean corpuscular volume are indirect biomarkers and are subject to the influence of age, gender and non-alcohol related diseases, among others. Direct metabolites of ethanol such as Ethyl glucuronide (EtG), ethyl sulphate (EtS) and phosphatidylethanol (PEth) are direct metabolites of ethanol, that are positive after intake of ethyl alcohol. They represent useful diagnostic tools for identifying alcohol use even more accurately than traditional biomarkers. Each of these drinking indicators remains positive in serum and urine for a characteristic time spectrum after the cessation of ethanol intake - EtG and EtS in urine up to 7 days, EtG in hair for months after ethanol has left the body. Applications include clinical routine use, emergency room settings, proof of abstinence in alcohol rehabilitation programmes, driving under influence offenders, workplace testing, assessment of alcohol intake in the context of liver transplantation and foetal alcohol syndrome. Due to their properties, they open up new perspectives for prevention, interdisciplinary cooperation, diagnosis of and therapy for alcohol-related problems.

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AIMS No standardized local thrombolysis regimen exists for the treatment of pulmonary embolism (PE). We retrospectively investigated efficacy and safety of fixed low-dose ultrasound-assisted catheter-directed thrombolysis (USAT) for intermediate- and high-risk PE. METHODS AND RESULTS Fifty-two patients (65 ± 14 years) of whom 14 had high-risk PE (troponin positive in all) and 38 intermediate-risk PE (troponin positive in 91%) were treated with intravenous unfractionated heparin and USAT using 10 mg of recombinant tissue plasminogen activator per device over the course of 15 h. Bilateral USAT was performed in 83% of patients. During 3-month follow-up, two [3.8%; 95% confidence interval (CI) 0.5-13%] patients died (one from cardiogenic shock and one from recurrent PE). Major non-fatal bleeding occurred in two (3.8%; 95% CI, 0.5-13%) patients: one intrathoracic bleeding after cardiopulmonary resuscitation requiring transfusion, one intrapulmonary bleeding requiring lobectomy. Mean pulmonary artery pressure decreased from 37 ± 9 mmHg at baseline to 25 ± 8 mmHg at 15 h (P < 0.001) and cardiac index increased from 2.0 ± 0.7 to 2.7 ± 0.9 L/min/m(2) (P < 0.001). Echocardiographic right-to-left ventricular end-diastolic dimension ratio decreased from 1.42 ± 0.21 at baseline to 1.06 ± 0.23 at 24 h (n = 21; P < 0.001). The greatest haemodynamic benefit from USAT was found in patients with high-risk PE and in those with symptom duration < 14 days. CONCLUSION A standardized catheter intervention approach using fixed low-dose USAT for the treatment of intermediate- and high-risk PE was associated with rapid improvement in haemodynamic parameters and low rates of bleeding complications and mortality.

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Pancreatic ductal adenocarcinoma (PDA) is one of the most aggressive malignancies with less than 5% of five year survival rate. New molecular markers and new therapeutic targets are urgently needed for patients with PDA. Oncogenic receptor tyrosine kinase Axl has been reported to be overexpressed in many types of human malignancies, including diffuse glioma, melanoma, osteosarcoma, and carcinomas of lung, colon, prostate, breast, ovary, esophagus, stomach, and kidney. However, the expression and functions of Axl in PDA are unclear. We hypothesized that Axl contributes to the development and progression of PDA. We examined Axl expression in 54 human PDA samples and their paired benign pancreatic tissue by immunohistochemistry, we found that Axl was overexpressed in 70% of stage II PDAs, but only 22% of benign ducts (P=0.0001). Axl overexpression was associated with higher frequencies of distant metastasis and was an independent prognostic factor for both poor overall and recurrence-free survivals in patients with stage II PDA (p = 0.03 and 0.04). Axl silencing by shRNA in pancreatic cancer cell lines, panc-28 and Panc-1, decreased tumor cell migration and invasion and sensitized PDA cells to apoptosis stimuli such as γ-irradiation and serum starvation. In addition, we found that Axl-mediated Akt and NF-κB activation and up regulation of MMP2 were involved in the invasion, migration and survival of PDA cells. Thus, we demonstrate that Axl plays an important role in the development and progression of PDA. Targeting Axl signaling pathway may represent a new approach for the treatment of PDA. To understand the molecular mechanisms of Axl overexpression in PDA, we found that Axl expression was down-regulated by hematopoietic progenitor kinase 1 (HPK1), a newly identified tumor suppressor in PDA. HPK1 is lost in over 95% of PDAs. Restoration of HPK1 in PDA cells down-regulated Axl expression. HPK1-mediated Axl degradation was inhibited by leupeptin, baflomycin A1, and monensin, suggesting that HPK1-mediated Axl degradation was through endocytosis-lysosome pathway. HPK1 interacted with and phosphorylated dynamin, a critical component of endocytosis pathway. Overexpression of dominant negative form of dynamin blocked the HPK1-mediated Axl degradation. Therefore we concluded that HPK1-mediated Axl degradation was through endocytosis-lysosome pathway and loss of HPK1 expression may contribute to Axl overexpression in PDAs.