16 resultados para Spengler, Osvaldo
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Resumo:
Glycan-binding antibodies form a significant subpopulation of both natural and acquired antibodies and play an important role in various immune processes. They are for example involved in innate immune responses, cancer, autoimmune diseases, and neurological disorders. In the present study, a microsphere-based flow-cytometric immunoassay (suspension array) was applied for multiplexed detection of glycan-binding antibodies in human serum. Several approaches for immobilization of glycoconjugates onto commercially available fluorescent microspheres were compared, and as the result, the design based on coupling of end-biotinylated glycopolymers has been selected. This method requires only minute amounts of glycans, similar to a printed glycan microarray. The resulting glyco-microspheres were used for detection of IgM and IgG antibodies directed against ABO blood group antigens. The possibility of multiplexing this assay was demonstrated with mixtures of microspheres modified with six different ABO related glycans. Multiplexed detection of anti-glycan IgM and IgG correlated well with singleplex assays (Pearson's correlation coefficient r = 0.95-0.99 for sera of different blood groups). The suspension array in singleplex format for A/B trisaccharide, H(di) and Le(x) microspheres corresponded well to the standard ELISA (r > 0.94). Therefore, the described method is promising for rapid, sensitive, and reproducible detection of anti-glycan antibodies in a multiplexed format.
Resumo:
The aim of the present study was to evaluate the diurnal rhythm of melatonin concentration in blood and milk of dairy cows. Blood was sampled and the entire milk was removed every hour and melatonin concentration was measured throughout 24 hours in June in 12 dairy cows (around 16 hours daylight). Both, blood plasma and milk melatonin concentration showed a diurnal pattern with high levels during scotoperiod and low levels during photoperiod. Average blood plasma melatonin was 16.2 +/- 2.3 pg/mL during the photoperiod (0800-2200h), started to increase at 2100h, and reached a plateau at 2300h (16.0 +/- 4.4 pg/mL). Peak concentration was reached at 0100h (25.4 +/- 5.6 pg/mL). At 0700h melatonin decreased to baseline level again. The melatonin pattern in milk paralleled the pattern in blood. However, the concentration of melatonin was much lower in milk than in blood with a maximum concentration of 2.9 +/- 0.6 pg/mL at all tested time points.
Resumo:
The lymphocyte transformation response to the mitogen phytohaemagglutinin (PHA) was determined in 15 well controlled insulin-dependent diabetics (IDD) with a history of insulin allergy or an acute insulin allergy. There was no significant difference in the PHA response of IDD and normal subjects matched in respect of age and sex. The response of peripheral blood lymphocytes to insulin (Actrapid) and an insulin zinc suspension (Monotard) was also determined. Fifty-three percent of IDD gave a positive reaction to Actrapid. Monotard produced positive reactions both in IDD and normal subjects. In normal subjects, a close correlation between the stimulation indices of Monotard and PHA was found (r = 0 . 966) suggesting that these stimulations depend on a common parameter namely, the reactivity to mitogens.
Resumo:
Maintaining a loyal customer base is challenging for “Deal of the Day” (DoD) platforms. DoD providers market and sell deals on products and services, yet it is the merchants who ultimately deliver those to consumers. Low entry and switching costs drive competition in this market. However, research on the determinants of user loyalty in the DoD context is limited. This study uses Grounded Theory and Structural Equation Modeling to explore the phenomenon of DoD platform loyalty. Particularly, monetary benefits, signal-to-noise ratio, perceived risk, and service friendliness during a merchant encounter emerge as powerful determinants of loyalty in this novel context.
Resumo:
Next-generation sequencing (NGS) is a valuable tool for the detection and quantification of HIV-1 variants in vivo. However, these technologies require detailed characterization and control of artificially induced errors to be applicable for accurate haplotype reconstruction. To investigate the occurrence of substitutions, insertions, and deletions at the individual steps of RT-PCR and NGS, 454 pyrosequencing was performed on amplified and non-amplified HIV-1 genomes. Artificial recombination was explored by mixing five different HIV-1 clonal strains (5-virus-mix) and applying different RT-PCR conditions followed by 454 pyrosequencing. Error rates ranged from 0.04-0.66% and were similar in amplified and non-amplified samples. Discrepancies were observed between forward and reverse reads, indicating that most errors were introduced during the pyrosequencing step. Using the 5-virus-mix, non-optimized, standard RT-PCR conditions introduced artificial recombinants in a fraction of at least 30% of the reads that subsequently led to an underestimation of true haplotype frequencies. We minimized the fraction of recombinants down to 0.9-2.6% by optimized, artifact-reducing RT-PCR conditions. This approach enabled correct haplotype reconstruction and frequency estimations consistent with reference data obtained by single genome amplification. RT-PCR conditions are crucial for correct frequency estimation and analysis of haplotypes in heterogeneous virus populations. We developed an RT-PCR procedure to generate NGS data useful for reliable haplotype reconstruction and quantification.
Resumo:
Background Vitamin D insufficiency has been associated with the occurrence of various types of cancer, but causal relationships remain elusive. We therefore aimed to determine the relationship between genetic determinants of vitamin D serum levels and the risk of developing hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). Methodology/Principal Findings Associations between CYP2R1, GC, and DHCR7 genotypes that are determinants of reduced 25-hydroxyvitamin D (25[OH]D3) serum levels and the risk of HCV-related HCC development were investigated for 1279 chronic hepatitis C patients with HCC and 4325 without HCC, respectively. The well-known associations between CYP2R1 (rs1993116, rs10741657), GC (rs2282679), and DHCR7 (rs7944926, rs12785878) genotypes and 25(OH)D3 serum levels were also apparent in patients with chronic hepatitis C. The same genotypes of these single nucleotide polymorphisms (SNPs) that are associated with reduced 25(OH)D3 serum levels were found to be associated with HCV-related HCC (P = 0.07 [OR = 1.13, 95% CI = 0.99–1.28] for CYP2R1, P = 0.007 [OR = 1.56, 95% CI = 1.12–2.15] for GC, P = 0.003 [OR = 1.42, 95% CI = 1.13–1.78] for DHCR7; ORs for risk genotypes). In contrast, no association between these genetic variations and liver fibrosis progression rate (P>0.2 for each SNP) or outcome of standard therapy with pegylated interferon-α and ribavirin (P>0.2 for each SNP) was observed, suggesting a specific influence of the genetic determinants of 25(OH)D3 serum levels on hepatocarcinogenesis. Conclusions/Significance Our data suggest a relatively weak but functionally relevant role for vitamin D in the prevention of HCV-related hepatocarcinogenesis.
Resumo:
BACKGROUND & AIMS: The genetic background of alcoholic liver diseases and their complications are increasingly recognized. A common polymorphism in the neurocan (NCAN) gene, which is known to be expressed in neuronal tissue, has been identified as a risk factor for non-alcoholic fatty liver disease (NAFLD). We investigated if this polymorphism may also be related to alcoholic liver disease (ALD) and hepatocellular carcinoma (HCC). METHODS: We analysed the distribution of the NCAN rs2228603 genotypes in 356 patients with alcoholic liver cirrhosis, 126 patients with alcoholic HCC, 382 persons with alcohol abuse without liver damage, 362 healthy controls and in 171 patients with hepatitis C virus (HCV) associated HCC. Furthermore, a validation cohort of 229 patients with alcoholic cirrhosis (83 with HCC) was analysed. The genotypes were determined by LightSNiP assays. The expression of NCAN was studied by RT-PCR and immunofluorescence microscopy. RESULTS: The frequency of the NCAN rs2228603 T allele was significantly increased in patients with HCC due to ALD (15.1%) compared to alcoholic cirrhosis without HCC (9.3%), alcoholic controls (7.2%), healthy controls (7.9%), and HCV associated HCC (9.1%). This finding was confirmed in the validation cohort (15.7% vs. 6.8%, OR=2.53; 95%CI: 1.36-4.68; p=0.0025) and by multivariate analysis (OR=1.840; 95%CI: 1.22-2.78; p=0.004 for carriage of the rs2228603 T allele). In addition, we identified and localised NCAN expression in human liver. CONCLUSIONS: NCAN is not only expressed in neuronal tissue, but also in the liver. Its rs2228603 polymorphism is a risk factor for HCC in ALD, but not in HCV infection.
Resumo:
Mit Kuno verbindet mich nicht allein das lnteresse an einer Theorie der Religion (Füssel, Huber, & Walpen, 1990). Mit dieser allerdings habe ich mich in den letztenJahren am intensivsten auseinandergesetzt. Daher erscheint es mir sinnvoll, zu dieser Thematik meinen Beitrag zu seiner Festschrift zu leisten. Kurzgefasst geht es darin um prosoziale Effekte religiôser Konstruktsysteme. Es lasst sich namlich zeigen, dass sie einen ideologischen Mechanismus zu neutralisieren vermôgen, wenn sie einen determinierenden Einfluss auf das Verhalten ausüben. Dabei spielt der Glaube, der nach einem allseits bekannten Diktum sogar Berge versetzen kann, eine entscheidende Rolle. Daher lese ich in dem Oberthema der Festschrift einen «Genitivus subjectivus». Es lautet dann: Suchet zuerst die Gerechtigkeit, die Gott realisiert bzw. realisieren wird. lch beginne mit der Darstellung einer sozialpsychologischen Theorie, die zu erklaren versucht, warum Menschen, die von einem ungerechten Ereignis getroffen werden, zu allem Überfluss auch noch die Schuld daran in die Schuhe geschoben bekommen. ln einem zweiten Schritt definiere ich, was ich unter religiôsen Konstruktsystemen verstehe und wie sie in sozialwissenschaftlichen Studien gemessen werden kônnen. Darauf aufbauend versuche ich zu prazisieren, wie religiôse Konstruktsysteme den Mechanismus der Schuldzuschreibung beeinflussen. Dazu greife ich aufDaten zurück, die ich 1999 in einer eigenen Untersuchung mit einer reprasentativen Stichprobe von Studierenden der Universitat Freiburg im Uechtland erhoben habe.
Resumo:
Cisplatin, a major antineoplastic drug used in the treatment of solid tumors, is a known nephrotoxin. This retrospective cohort study evaluated the prevalence and severity of cisplatin nephrotoxicity in 54 children and its impact on height and weight.We recorded the weight, height, serum creatinine, and electrolytes in each cisplatin cycle and after 12 months of treatment. Nephrotoxicity was graded as follows: normal renal function (Grade 0); asymptomatic electrolyte disorders, including an increase in serum creatinine, up to 1.5 times baseline value (Grade 1); need for electrolyte supplementation <3 months and/or increase in serum creatinine 1.5 to 1.9 times from baseline (Grade 2); increase in serum creatinine 2 to 2.9 times from baseline or need for electrolyte supplementation for more than 3 months after treatment completion (Grade 3); and increase in serum creatinine ≥3 times from baseline or renal replacement therapy (Grade 4).Nephrotoxicity was observed in 41 subjects (75.9%). Grade 1 nephrotoxicity was observed in 18 patients (33.3%), Grade 2 in 5 patients (9.2%), and Grade 3 in 18 patients (33.3%). None had Grade 4 nephrotoxicity. Nephrotoxicity patients were younger and received higher cisplatin dose, they also had impairment in longitudinal growth manifested as statistically significant worsening on the height Z Score at 12 months after treatment. We used a multiple logistic regression model using the delta of height Z Score (baseline-12 months) as dependent variable in order to adjust for the main confounder variables such as: germ cell tumor, cisplatin total dose, serum magnesium levels at 12 months, gender, and nephrotoxicity grade. Patients with nephrotoxicity Grade 1 where at higher risk of not growing (OR 5.1, 95% CI 1.07-24.3, P=0.04). The cisplatin total dose had a significant negative relationship with magnesium levels at 12 months (Spearman r=-0.527, P=<0.001).
Resumo:
BACKGROUND Nail unit melanoma (NUM) is a variant of acral lentiginous melanoma. The differential diagnosis is wide but an acquired brown streak in the nail of a fair-skinned adult person must be considered a potential melanoma. Dermoscopy helps clinicians to more accurately decide if a nail apparatus biopsy is necessary. OBJECTIVE Detailed evaluation of clinical and dermoscopy features and description of conservative surgery of in situ NUM. METHODS Retrospective study of in situ NUM diagnosed and treated with conservative surgical management in the authors' center from 2008 to 2013. RESULTS Six cases of NUM were identified: 2 male and 4 female patients, age range at diagnosis of 44 to 76 years. All patients underwent complete nail unit removal with at least 6-mm security margins around the anatomic boundaries of the nail. The follow-up varies from 4 to 62 months. CONCLUSION Nail unit melanomas pose a difficult diagnostic and therapeutic challenge. Wide excision is sufficient, whereas phalanx amputation is unnecessary and associated with significant morbidity for patients with in situ or early invasive melanoma. Full-thickness skin grafting or second-intention healing after total nail unit excision is a simple procedure providing a good functional and cosmetic outcome.