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1.
J Lipid Res ; 64(12): 100473, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37949369

RESUMO

Protein aggregates arise naturally under normal physiological conditions, but their formation is accelerated by age or stress-induced protein misfolding. When the stressful event dissolves, these aggregates are removed by mechanisms, such as aggrephagy, chaperone-mediated autophagy, refolding attempts, or the proteasome. It was recently shown that mitochondria in yeast cells may support these primarily cytosolic processes. Protein aggregates attach to mitochondria, and misfolded proteins are transported into the matrix and degraded by mitochondria-specific proteases. Using a proximity labeling method and colocalization with an established stress granule (SG) marker, we were able to show that these mitochondria-localized aggregates that harbor the "super aggregator" Ola1p are, in fact, SGs. Our in vivo and in vitro studies have revealed that Ola1p can be transferred from mitochondria to lipid droplets (LDs). This "mitochondria to LD" aggregate transfer dampens proteotoxic effects. The LD-based protein aggregate removal system gains importance when other proteolytic systems fail. Furthermore, we were able to show that the distribution of SGs is drastically altered in LD-deficient yeast cells, demonstrating that LDs play a role in the SG life cycle.


Assuntos
Gotículas Lipídicas , Saccharomyces cerevisiae , Gotículas Lipídicas/metabolismo , Mitocôndrias/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Agregados Proteicos , Saccharomyces cerevisiae/metabolismo , Grânulos de Estresse
2.
Int J Mol Sci ; 24(5)2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36901755

RESUMO

Psoriasis is an inflammatory skin disease characterized by increased neo-vascularization, keratinocyte hyperproliferation, a pro-inflammatory cytokine milieu and immune cell infiltration. Diacerein is an anti-inflammatory drug, modulating immune cell functions, including expression and production of cytokines, in different inflammatory conditions. Therefore, we hypothesized that topical diacerein has beneficial effects on the course of psoriasis. The current study aimed to evaluate the effect of topical diacerein on imiquimod (IMQ)-induced psoriasis in C57BL/6 mice. Topical diacerein was observed to be safe without any adverse side effects in healthy or psoriatic animals. Our results demonstrated that diacerein significantly alleviated the psoriasiform-like skin inflammation over a 7-day period. Furthermore, diacerein significantly diminished the psoriasis-associated splenomegaly, indicating a systemic effect of the drug. Remarkably, we observed significantly reduced infiltration of CD11c+ dendritic cells (DCs) into the skin and spleen of psoriatic mice with diacerein treatment. As CD11c+ DCs play a pivotal role in psoriasis pathology, we consider diacerein to be a promising novel therapeutic candidate for psoriasis.


Assuntos
Dermatite , Psoríase , Animais , Camundongos , Baço/metabolismo , Camundongos Endogâmicos C57BL , Pele/metabolismo , Psoríase/patologia , Dermatite/metabolismo , Citocinas/metabolismo , Células Dendríticas/metabolismo , Modelos Animais de Doenças , Camundongos Endogâmicos BALB C
3.
Clin Chem Lab Med ; 60(9): 1356-1364, 2022 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-35696446

RESUMO

OBJECTIVES: Although laboratory result presentation may lead to information overload and subsequent missed or delayed diagnosis, little has been done in the past to improve this post-analytical issue. We aimed to investigate the efficiency, efficacy and user satisfaction of alternative report formats. METHODS: We redesigned cumulative (sparkline format) and single reports (improved tabular and z-log format) and tested these on 46 physicians, nurses and medical students in comparison to the classical tabular formats, by asking standardized questions on general items on the reports as well as on suspected diagnosis and follow-up treatment or diagnostics. RESULTS: Efficacy remained at a very high level both in the new formats as well as in the classical formats. We found no significant difference in any of the groups. Efficiency improved in all groups when using the sparkline cumulative format and marginally when showing the improved tabular format. When asking medical questions, efficiency and efficacy remained similar between report formats and groups. All alternative reports were subjectively more attractive to the majority of participants. CONCLUSIONS: Showing cumulative reports as a graphical display led to faster detection of general information on the report with the same level of correctness. Considering the familiarity bias of the classical single report formats, the borderline-significant improvement of the alternative tabular format and the non-inferiority of the z-log format, suggests that single reports might benefit from some improvements derived from basic information design.


Assuntos
Química Clínica , Satisfação Pessoal , Humanos , Laboratórios , Relatório de Pesquisa
4.
BMC Emerg Med ; 22(1): 38, 2022 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-35279068

RESUMO

INTRODUCTION: Intoxications are common in intensive care units (ICUs). The number of causative substances is large, mortality usually low. This retrospective cohort study aims to characterize differences of intoxicated compared to general ICU patients, point out variations according to causative agents, as well as to highlight differences between survivors and non-survivors among intoxicated individuals in a large-scale multi-center analysis. METHODS: A total of 105,998 general ICU patients and 4,267 individuals with the admission diagnoses "overdose" and "drug toxicity" from the years 2014 and 2015 where included from the eICU Collaborative Research Database. In addition to comparing these groups with respect to baseline characteristics, intensive care measures and outcome parameters, differences between survivors and non-survivors from the intoxication group, as well as the individual groups of causative substances were investigated. RESULTS: Intoxicated patients were younger (median 41 vs. 66 years; p<0.001), more often female (55 vs. 45%; p<0.001), and normal weighted (36% vs. 30%; p<0.001), whereas more obese individuals where observed in the other group (37 vs. 31%; p<0.001). Intoxicated individuals had a significantly lower mortality compared to general ICU patients (1% vs. 10%; aOR 0.07 95%CI 0.05-0.11; p<0.001), a finding which persisted after multivariable adjustment (aOR 0.17 95%CI 0.12-0.24; p<0.001) and persisted in all subgroups. Markers of disease severity (SOFA-score: 3 (1-5) vs. 4 (2-6) pts.; p<0.001) and frequency of vasopressor use (5 vs. 15%; p<0.001) where lower, whereas rates of mechanical ventilation where higher (24 vs. 26%; p<0.001) in intoxicated individuals. There were no differences with regard to renal replacement therapy in the first three days (3 vs. 4%; p=0.26). In sensitivity analysis (interactions for age, sex, ethnicity, hospital category, maximum initial lactate, mechanical ventilation, and vasopressor use), a trend towards lower mortality in intoxicated patients persisted in all subgroups. CONCLUSION: This large-scale retrospective analysis indicates a significantly lower mortality of intoxicated individuals compared to general ICU patients.


Assuntos
Cuidados Críticos , Unidades de Terapia Intensiva , Feminino , Mortalidade Hospitalar , Humanos , Masculino , Respiração Artificial , Estudos Retrospectivos , Sobreviventes
5.
Clin Chem Lab Med ; 58(9): 1565-1571, 2020 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-32305953

RESUMO

Background: Laboratory overutilization is associated with diagnostic error and potential patient risk. We applied a demand management strategy in collaboration with the local Department of Cardiology to reduce the cardiac markers high-sensitive troponin T (hsTropT) and N-terminal pro brain natriuretic peptide (NTproBNP) in laboratory ordering profiles (LOPs). The present study aimed to retrospectively evaluate the implemented strategies. Methods: Strategies included educational measures and evidence-guided, active test de-selection from all cardiology ward LOPs, and/or permanent removal from LOPs. Tests remained available at all times. We evaluated overutilization by reductions in monthly orders, and assessed differences in 30-day all-cause readmission rate and length of patients' hospital stay. Results: Overall, we observed a mean reduction of 66.1% ± 7.6% (n = 277 ± 31) in hsTropT tests. Educational measures effectively reduced NTproBNP orders by 52.8% ± 17.7% (n = 60 ± 20). Permanent removal of tests from LOPs additionally decreased orders to a final extent of 75.8% ± 8.0% (n = 322 ± 31) in NTproBNP tests. The 30-day readmission rate and overall length of hospital stay did not increase. Conclusions: Our results indicate that cardiac markers in routine care are subject to extensive overutilization when used within LOPs. Educational measures are an effective strategy to overcome the overutilization of cardiac markers but may be more effective when combined with the removal of cardiac markers from LOPs.


Assuntos
Testes Diagnósticos de Rotina/economia , Cardiopatias/sangue , Unidades Hospitalares , Biomarcadores/sangue , Humanos , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Estudos Retrospectivos , Troponina T
6.
Molecules ; 25(21)2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33143278

RESUMO

Lipid droplets (LDs) were considered as a mere lipid storage organelle for a long time. Recent evidence suggests that LDs are in fact distinct and dynamic organelles with a specialized proteome and functions in many cellular roles. As such, LDs contribute to cellular signaling, protein and lipid homeostasis, metabolic diseases and inflammation. In line with the multitude of functions, LDs interact with many cellular organelles including mitochondria, peroxisomes, lysosomes, the endoplasmic reticulum and the nucleus. LDs are highly mobile and dynamic organelles and impaired motility disrupts the interaction with other organelles. The reduction of interorganelle contacts results in a multitude of pathophysiologies and frequently in neurodegenerative diseases. Contacts not only supply lipids for ß-oxidation in mitochondria and peroxisomes, but also may include the transfer of toxic lipids as well as misfolded and harmful proteins to LDs. Furthermore, LDs assist in the removal of protein aggregates when severe proteotoxic stress overwhelms the proteasomal system. During imbalance of cellular lipid homeostasis, LDs also support cellular detoxification. Fine-tuning of LD function is of crucial importance and many diseases are associated with dysfunctional LDs. We summarize the current understanding of LDs and their interactions with organelles, providing a storage site for harmful proteins and lipids during cellular stress, aging inflammation and various disease states.


Assuntos
Envelhecimento/metabolismo , Gotículas Lipídicas/metabolismo , Metabolismo dos Lipídeos , Doenças Neurodegenerativas/metabolismo , Proteoma/metabolismo , Estresse Fisiológico , Animais , Retículo Endoplasmático/metabolismo , Humanos
7.
Neurobiol Dis ; 121: 34-46, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30236862

RESUMO

Parkinson's disease (PD) is the second most common neurodegenerative disease worldwide. PGC-1α, encoded by PPARGC1A, is a transcriptional co-activator that has been implicated in the pathogenesis of neurodegenerative disorders. We recently discovered multiple new PPARGC1A transcripts that initiate from a novel promoter located far upstream of the reference gene promoter, are CNS-specific and are more abundant than reference gene transcripts in whole brain. These CNS-specific transcripts encode two main full-length and several truncated isoforms via alternative splicing. Truncated CNS-isoforms include 17 kDa proteins that lack the second LXXLL motif serving as an interaction site for several nuclear receptors. We now determined expression levels of CNS- and reference gene transcripts in 5 brain regions of 21, 8, and 13 deceased subjects with idiopathic PD, Lewy body dementia and controls without neurodegenerative disorders, respectively. We observed reductions of CNS-specific transcripts (encoding full-length isoforms) only in the substantia nigra pars compacta of PD and Lewy body dementia. However, in the substantia nigra and globus pallidus of PD cases we found an up-regulation of transcripts encoding the 17 kDa proteins that inhibited the co-activation of several transcription factors by full-length PGC-1α proteins in transfection assays. In two established animal models of PD, the PPARGC1A expression profiles differed from the profile in human PD in that the levels of CNS- and reference gene transcripts were decreased in several brain regions. Furthermore, we identified haplotypes in the CNS-specific region of PPARGC1A that appeared protective for PD in a clinical cohort and a post-mortem sample (P = .0002). Thus, functional and genetic studies support a role of the CNS-specific PPARGC1A locus in PD.


Assuntos
Encéfalo/metabolismo , Doença de Parkinson/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Idoso , Idoso de 80 Anos ou mais , Animais , Feminino , Loci Gênicos , Humanos , Masculino , Camundongos Endogâmicos C57BL , Isoformas de Proteínas/genética
8.
Clin Chem Lab Med ; 57(12): 1888-1896, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31377734

RESUMO

Background Published evidence on the risk of additive carryover during phlebotomy remains elusive. We aimed to assess potential carryover of citrated and heparinized blood and the relative volume needed to bias clinical chemistry and coagulation tests. Methods We simulated standardized phlebotomies to quantify the risk of carryover of citrate and heparin additives in distilled water, using sodium and lithium as surrogates. We also investigated the effects of contamination of heparinized blood samples with increasing volumes of citrated blood and pure citrate on measurements of sodium, potassium, chloride, magnesium, total and ionized calcium and phosphate. Likewise, we studied the effects of contamination of citrated blood samples with increasing volumes of heparinized blood on heparin (anti-Xa) activity, lithium, activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT). We interpreted these results based on measurement deviations beyond analytical, biological and clinical significance. Results Standardized phlebotomy simulations revealed no significant differences in concentration of surrogate markers. Clinically significant alterations were observed after contamination of heparinized blood samples with volumes of citrated blood beyond 5-50 µL for ionized calcium and beyond 100-1000 µL for sodium, chloride and total calcium. Investigations of pure citrate carryover revealed similar results at somewhat lower volumes. Heparinized blood carryover showed clinically significant interference of coagulation testing at volumes beyond 5-100 µL. Conclusions Our results suggest that during a standardized phlebotomy, heparin or citrate contamination is highly unlikely. However, smaller volumes are sufficient to severely alter test results when deviating from phlebotomy guidelines.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Ácido Cítrico/análise , Heparina/análise , Anticoagulantes , Coagulação Sanguínea/efeitos dos fármacos , Testes de Coagulação Sanguínea/métodos , Citratos , Ácido Cítrico/sangue , Contaminação de Equipamentos/prevenção & controle , Heparina/sangue , Humanos , Tempo de Tromboplastina Parcial , Flebotomia/métodos , Flebotomia/normas , Fase Pré-Analítica/métodos , Tempo de Protrombina , Tempo de Trombina
9.
Planta Med ; 85(16): 1233-1241, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31610603

RESUMO

The chroman-like chalcone Xanthohumol C, originally found in hops, was demonstrated to be a potent neuroregenerative and neuroprotective natural product and therefore constitutes a strong candidate for further pharmaceutical research. The bottleneck for in vivo experiments is the low water solubility of this chalcone. Consequently, we developed and validated a suitable formulation enabling in vivo administration. Cyclodextrins were used as water-soluble and nontoxic complexing agents, and the complex of Xanthohumol C and 2-hydroxypropyl-ß-cyclodextrin was characterized using HPLC, HPLC-MS, NMR, and differential scanning calorimetry. The water solubility of Xanthohumol C increases with increasing concentrations of cyclodextrin. Using 50 mM 2-hydroxypropyl-ß-cyclodextrin, solubility was increased 650-fold. Furthermore, in vitro bioactivity of Xanthohumol C in free and complexed form did not significantly differ, suggesting the release of Xanthohumol C from 2-hydroxypropyl-ß-cyclodextrin. Finally, a small-scaled in vivo experiment in a rat model showed that after i. p. administration of the complex, Xanthohumol C can be detected in serum, the brain, and the cerebrospinal fluid at 1 and 6 h post-administration. Mean (± SD) Xanthohumol C serum concentrations after 1, 6, and 12 h were determined as 463.5 (± 120.9), 61.9 (± 13.4), and 9.3 (± 0.8) ng/mL upon i. v., and 294.3 (± 22.4), 45.5 (± 0.7), and 13 (± 1.0) ng/mL after i. p. application, respectively. Accordingly, the formulation of Xanthohumol C/2-hydroxypropyl-ß-cyclodextrin is suitable for further in vivo experiments and further pharmaceutical research aiming for the determination of its neuroregenerative potential in animal disease models.


Assuntos
2-Hidroxipropil-beta-Ciclodextrina/administração & dosagem , Benzopiranos/administração & dosagem , 2-Hidroxipropil-beta-Ciclodextrina/química , 2-Hidroxipropil-beta-Ciclodextrina/farmacocinética , Animais , Benzopiranos/química , Benzopiranos/farmacocinética , Disponibilidade Biológica , Varredura Diferencial de Calorimetria , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Espectroscopia de Ressonância Magnética , Ratos , Solubilidade
10.
J Am Acad Dermatol ; 78(5): 892-901.e7, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29410318

RESUMO

BACKGROUND: Epidermolysis bullosa simplex (EBS) is a rare genetic, blistering skin disease for which there is no cure. Treatments that address the pathophysiology of EBS are needed. OBJECTIVE: Compare the impact of 1% diacerein cream with placebo in reducing the number of blisters in EBS. METHODS: In a randomized, placebo-controlled, phase 2/3 trial we used a 1% diacerein topical formulation to treat defined skin areas in 17 patients. In a 2-period crossover trial, patients were randomized to either placebo or diacerein for a 4-week treatment and a 3-month follow-up in period 1. After a washout, patients were crossed over during period 2. The prespecified primary end point was the proportion of patients with a reduction of number of blisters by more than 40% from baseline in selected areas over the treatment episode. RESULTS: Of the patients receiving diacerein, 86% in episode 1 and 37.5% in episode 2 met the primary end point (vs 14% and 17% with placebo, respectively). This effect was still significant after the follow-up. Changes in absolute blister numbers were significant for the diacerein group only. No adverse effects were observed. LIMITATIONS: Low patient numbers and no invasive data acquisition because of clinical burden in children. CONCLUSION: This trial provides evidence of the impact of 1% diacerein cream in the treatment of EBS.


Assuntos
Antraquinonas/uso terapêutico , Epidermólise Bolhosa Simples/diagnóstico , Epidermólise Bolhosa Simples/tratamento farmacológico , Produção de Droga sem Interesse Comercial , Administração Tópica , Anti-Inflamatórios , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Método Duplo-Cego , Esquema de Medicação , Feminino , Seguimentos , Humanos , Masculino , Cooperação do Paciente , Medição de Risco , Índice de Gravidade de Doença , Resultado do Tratamento
11.
Am J Gastroenterol ; 112(1): 102-110, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27527746

RESUMO

OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) is closely linked to obesity; however, 5-8% of lean subjects also have evidence of NAFLD. We aimed to investigate clinical, genetic, metabolic and lifestyle characteristics in lean Caucasian subjects with NAFLD. METHODS: Data from 187 subjects allocated to one of the three groups according to body mass index (BMI) and hepatic steatosis on ultrasound were obtained: lean healthy (BMI≤25 kg/m2, no steatosis, N=71), lean NAFLD (BMI≤25 kg/m2, steatosis, N=55), obese NAFLD (BMI≥30 kg/m2, steatosis; N=61). All subjects received a detailed clinical and laboratory examination including oral glucose tolerance test. The serum metabolome was assessed using the Metabolomics AbsoluteIDQ p180 kit (BIOCRATES Life Sciences). Genotyping for single-nucleotide polymorphisms (SNPs) associated with NAFLD was performed. RESULTS: Lean NAFLD subjects had fasting insulin concentrations similar to lean healthy subjects but had markedly impaired glucose tolerance. Lean NAFLD subjects had a higher rate of the mutant PNPLA3 CG/GG variant compared to lean controls (P=0.007). Serum adiponectin concentrations were decreased in both NAFLD groups compared to controls (P<0.001 for both groups) The metabolomics study revealed a potential role for various lysophosphatidylcholines (lyso-PC C18:0, lyso-PC C17:0) and phosphatidylcholines (PCaa C36:3; false discovery rate (FDR)-corrected P-value<0.001) as well as lysine, tyrosine, and valine (FDR<0.001). CONCLUSIONS: Lean subjects with evidence of NAFLD have clinically relevant impaired glucose tolerance, low adiponectin concentrations and a distinct metabolite profile with an increased rate of PNPLA3 risk allele carriage.


Assuntos
Adiponectina/metabolismo , Intolerância à Glucose/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/metabolismo , Adulto , Idoso , Alelos , Índice de Massa Corporal , Estudos de Casos e Controles , Feminino , Genótipo , Intolerância à Glucose/epidemiologia , Humanos , Insulina/metabolismo , Resistência à Insulina , Lipase/genética , Fígado/diagnóstico por imagem , Fígado/metabolismo , Lisina/metabolismo , Lisofosfatidilcolinas/metabolismo , Masculino , Proteínas de Membrana/genética , Metabolômica , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/diagnóstico por imagem , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Obesidade/complicações , Fosfatidilcolinas/metabolismo , Polimorfismo de Nucleotídeo Único , Tirosina/metabolismo , Ultrassonografia , Valina/metabolismo , População Branca
12.
Clin Chem Lab Med ; 55(8): 1129-1134, 2017 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-28107171

RESUMO

BACKGROUND: Blood collection through intravenous (IV) catheters is a common practice at emergency departments (EDs). This technique is associated with higher in vitro hemolysis rates and may even be amplified by the use of vacuum collection tubes. Our aim was to investigate the association of five different vacuum tubes with hemolysis rates in comparison to an aspiration system under real-life conditions and to propose an equation to estimate the amount of hemolysis, depending on the vacuum collection tube type. METHODS: We retrospectively evaluated hemolysis data of plasma samples from our ED, where blood is drawn through IV catheters. Over the past 5 years, we compared 19,001 hemolysis index values amongst each other and against the respective vacuum pressure (Pv) of the collection tubes, which were used within the six observational periods. RESULTS: The highest hemolysis rates were associated with full-draw evacuated tubes. Significantly reduced hemolysis was observed for two kinds of partial-draw tubes. The hemolysis rate of one partial-draw blood collection tube was comparable to those of the aspiration system. Regression analysis of Pv and mean free hemoglobin (fHb) values yielded the formula fHb (g/L)=0.0082*Pv2-0.1143*Pv+ 0.5314 with an R2 of 0.99. CONCLUSIONS: If IV catheters are used for blood collection, hemolysis rates directly correlate with the vacuum within the tubes and can be estimated by the proposed formula. By the use of partial-draw vacuum blood collection tubes, hemolysis rates in IV catheter collections can be reduced to levels comparable with collections performed by aspiration systems.


Assuntos
Coleta de Amostras Sanguíneas/instrumentação , Catéteres , Hemólise , Vácuo , Estudos de Coortes , Hemoglobinas/análise , Humanos , Estudos Retrospectivos
13.
Clin Chem Lab Med ; 54(12): 1987-1992, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27235673

RESUMO

BACKGROUND: Hemolytic samples are one of the most challenging preanalytical issues in laboratory medicine. Even causes leading to hemolytic specimen are various, including phlebotomy practices. Respective educational interventions as well as the reduction of the number of people involved in blood collections are claimed to influence the sample quality for the better. In our hospital 70 junior doctors were in charge of routine phlebotomy until 2012, when this task was shifted to 874 nurses, including a preceding training in phlebotomy and preanalytics. Our aim was to evaluate the impact of this training effect and the increase of people involved on sample quality. METHODS: The hemolysis index (HI) of 43,875 samples was measured before (n=21,512) and after (n=22,363) the switch of blood collection responsibilities. Differences in overall hemolysis rates and the amount of plasma samples with a concentration of free hemoglobin (fHb) above 0.5 g/L and 1 g/L were calculated. RESULTS: Overall HI as well as the percentage of samples with an fHb concentration >0.5 g/L decreased after the responsibility for phlebotomy changed. The rate of samples with an fHb concentration >1 g/L remained unchanged. CONCLUSIONS: Hemolysis rates were reduced upon passing phlebotomy tasks from untrained physicians on to a trained nursing staff. We therefore conclude that the number of people performing phlebotomy seems to play a minor role, compared to the effect of a standardized training. However, whether a reduction in the number of people involved in blood collection could lead to further improvement of sample quality, remains to be investigated in future studies.


Assuntos
Competência Clínica , Hemólise , Enfermeiras e Enfermeiros , Flebotomia/normas , Médicos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Enfermeiras e Enfermeiros/normas , Médicos/normas , Adulto Jovem
14.
Eur J Immunol ; 44(7): 2175-87, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24668151

RESUMO

Activation-induced deaminase (AID) is a DNA-mutating enzyme that mediates class-switch recombination as well as somatic hypermutation of antibody genes in B cells. Due to off-target activity, AID is implicated in lymphoma development by introducing genome-wide DNA damage and initiating chromosomal translocations such as c-myc/IgH. Several alternative splice transcripts of AID have been reported in activated B cells as well as malignant B cells such as chronic lymphocytic leukemia (CLL). As most commercially available antibodies fail to recognize alternative splice variants, their abundance in vivo, and hence their biological significance, has not been determined. In this study, we assessed the protein levels of AID splice isoforms by introducing an AID splice reporter construct into cell lines and primary CLL cells from patients as well as from WT and TCL1(tg) C57BL/6 mice (where TCL1 is T-cell leukemia/lymphoma 1). The splice construct is 5'-fused to a GFP-tag, which is preserved in all splice isoforms and allows detection of translated protein. Summarizing, we show a thorough quantification of alternatively spliced AID transcripts and demonstrate that the corresponding protein abundances, especially those of splice variants AID-ivs3 and AID-ΔE4, are not stoichiometrically equivalent. Our data suggest that enhanced proteasomal degradation of low-abundance proteins might be causative for this discrepancy.


Assuntos
Processamento Alternativo , Citidina Desaminase/genética , Leucemia Linfocítica Crônica de Células B/enzimologia , Animais , Citidina Desaminase/análise , Células HEK293 , Humanos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase em Tempo Real
15.
Clin Chem Lab Med ; 53(8): 1271-8, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25720083

RESUMO

BACKGROUND: The order of draw is regarded as a preanalytical issue to prevent carryover of additives during blood collection. Our objective was to prove the theory of ethylenediaminetetraacetic acid (EDTA) carryover for a closed vacuum system and the influence of EDTA on concentrations of selected biomarkers. METHODS: To test the carryover of EDTA, a blood collection with tripotassium EDTA (K3EDTA) and subsequent non-additive tubes was simulated using distilled water as substitute for blood. EDTA concentrations were measured by tandem mass spectrometry. Then we added increasing concentrations of EDTA to heparinized blood and measured routine biomarkers, thereby simulating a carryover of EDTA whole blood and pure EDTA, respectively. Additionally, we tested for EDTA contamination and biomarker alteration in samples collected from 10 healthy volunteers by a syringe with subsequent transfer into sample tubes. RESULTS: No EDTA contamination was detected in samples collected subsequent to a K3EDTA tube when adhering to guidelines of blood sampling. Magnesium, calcium, and potassium levels were altered by artificial K3EDTA whole-blood contamination as well as when adding 1 µL pure K3EDTA. Iron values were altered at EDTA concentrations of 4.4 mmol/L. All other parameters remained unaffected. A slight EDTA carryover was observed in syringe collection and subsequent transfer into EDTA and heparin tubes, however, without any biomarker alteration. CONCLUSIONS: An EDTA carryover during blood collection using a closed vacuum system is highly unlikely. Even if carryover of EDTA whole blood occurs, an absolute volume larger than 10 µL would be necessary to alter test results. However, contamination of samples with preloaded pure K3EDTA solution by severe neglect of current recommendations in blood collection may significantly alter testing results.


Assuntos
Coleta de Amostras Sanguíneas/métodos , Ácido Edético/sangue , Cromatografia Líquida , Humanos , Espectrometria de Massas em Tandem
17.
Proc Natl Acad Sci U S A ; 109(22): 8658-63, 2012 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-22586098

RESUMO

The large protein superfamily of NADPH oxidases (NOX enzymes) is found in members of all eukaryotic kingdoms: animals, plants, fungi, and protists. The physiological functions of these NOX enzymes range from defense to specialized oxidative biosynthesis and to signaling. In filamentous fungi, NOX enzymes are involved in signaling cell differentiation, in particular in the formation of fruiting bodies. On the basis of bioinformatics analysis, until now it was believed that the genomes of unicellular fungi like Saccharomyces cerevisiae and Schizosaccharomyces pombe do not harbor genes coding for NOX enzymes. Nevertheless, the genome of S. cerevisiae contains nine ORFs showing sequence similarity to the catalytic subunits of mammalian NOX enzymes, only some of which have been functionally assigned as ferric reductases involved in iron ion transport. Here we show that one of the nine ORFs (YGL160W, AIM14) encodes a genuine NADPH oxidase, which is located in the endoplasmic reticulum (ER) and produces superoxide in a NADPH-dependent fashion. We renamed this ORF YNO1 (yeast NADPH oxidase 1). Overexpression of YNO1 causes YCA1-dependent apoptosis, whereas deletion of the gene makes cells less sensitive to apoptotic stimuli. Several independent lines of evidence point to regulation of the actin cytoskeleton by reactive oxygen species (ROS) produced by Yno1p.


Assuntos
Actinas/metabolismo , Apoptose , NADPH Oxidases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Sequência de Aminoácidos , Caspases/genética , Caspases/metabolismo , Citoesqueleto/metabolismo , Retículo Endoplasmático/enzimologia , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Microscopia de Fluorescência , Microscopia de Contraste de Fase , Dados de Sequência Molecular , Mutação , NADPH Oxidases/classificação , NADPH Oxidases/genética , Fases de Leitura Aberta/genética , Filogenia , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Superóxidos/metabolismo
18.
Eur J Anaesthesiol ; 32(11): 781-9, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25782662

RESUMO

BACKGROUND: Carotid endarterectomy is widely performed under regional anaesthesia. Ultrasound guidance is increasingly used in many regional anaesthetic procedures to improve safety and efficacy, and because it can reduce the amount of local anaesthetic required. Despite this, an ideal approach and dosing regimen for cervical plexus block remain elusive. OBJECTIVE: The aim of this study was to compare two different concentrations of ropivacaine in terms of analgesic adequacy, haemodynamic effects and plasma concentration using an ultrasound-guided triple approach for intermediate cervical plexus blockade. DESIGN: A randomised, placebo-controlled, blinded study. SETTING: University Clinic Salzburg, Department of Anaesthesiology, Perioperative Medicine and Intensive Care, Paracelsus Medical University, Salzburg, Austria, from 16 November 2012 to 17 September 2013. PATIENTS: Forty-six patients prospectively randomised to receive ultrasound-guided intermediate cervical block with either 20 ml ropivacaine 0.75% or 20 ml ropivacaine 0.375% each with 20 ml prilocaine 1%. INTERVENTION: After subcutaneous infiltration, blocks were performed using ultrasound-guided infiltration below the sternocleidomastoid muscle, and ultrasound-guided infiltration of the carotid sheath. Ropivacaine and prilocaine plasma concentrations were measured at intervals. MAIN OUTCOME: The primary study endpoint was the volume of supplementary lidocaine 1% required to achieve adequate surgical anaesthesia. Perioperative haemodynamic variables and pain scores were recorded. RESULTS: There was no statistical difference in the volume of supplementary lidocaine given: 5.0 (±3.63) ml in the ropivacaine 0.375% group and 5.17 (±2.76) ml in the ropivacaine 0.75% group (P = 0.846). Pain scores were similarly low across both groups. Measured concentrations of ropivacaine and prilocaine did not reach toxic levels in either group. Levels of ropivacaine were approximately two-fold higher in the 0.75% group [mean area under the curve (AUC) 10 531.11 (±2912.84) vs. 5264.34 ng (±1594.69), P < 0.0001]. Perioperative cardiovascular stability was excellent in both groups. There were no serious block-related complications. CONCLUSION: An ultrasound-guided intermediate block provides adequate anaesthesia for carotid thrombendarterectomy with a little need for supplementary local anaesthetic. Use of 0.375% ropivacaine provided similarly effective analgesia as 0.75%, but resulted in significantly lower plasma concentrations. TRIAL REGISTRATION: The study was registered at the European Clinical Trial Database (Eudra CT No.: 2012-002769) as well as at ClinicalTrials.gov (NCT01759940).


Assuntos
Amidas/administração & dosagem , Anestésicos Locais/administração & dosagem , Bloqueio do Plexo Cervical/métodos , Endarterectomia das Carótidas/métodos , Prilocaína/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Áustria , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Ropivacaina , Ultrassonografia de Intervenção
19.
Hum Mol Genet ; 21(15): 3461-73, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22589246

RESUMO

PGC-1α has been implicated in the pathogenesis of neurodegenerative disorders. Several single-nucleotide polymorphisms (SNPs) located in two separate haplotype blocks of PPARGC1A have shown associations with Huntington's disease (HD) and Parkinson's disease, but causative SNPs have not been identified. One SNP (rs7665116) was located in a highly conserved 233 bp region of intron 2. To determine whether rs7665116 is located in an alternative exon, we performed 5'-RLM-RACE from exon 3 and discovered multiple new transcripts that initiated from a common novel promoter located 587 kb upstream of exon 2, but did not contain the conserved region harboring rs7665116. Using real-time polymerase chain reaction, RNase protection assays and northern blotting, we show that the majority of these transcripts are brain specific and are at least equally or perhaps more abundant than the reference sequence PPARGC1A transcripts in whole brain. Two main transcripts containing independent methionine start codons encode full-length brain-specific PGC-1α proteins that differ only at their N-termini (NTs) from PGC-1α, encoded by the reference sequence. Additional truncated isoforms containing these NTs that are similar to NT-PGC-1α exist. Other transcripts may encode potential dominant negative forms, as they are predicted to lack the second LXXLL motif that serves as an interaction site for several nuclear receptors. Furthermore, we show that the new promoter is active in neuronal cell lines and describe haplotypes encompassing this region that are associated with HD age of onset. The discovery of such a large PPARGC1A genomic locus and multiple isoforms in brain warrants further functional studies and may provide new tissue-specific targets for treating neurodegenerative diseases.


Assuntos
Encéfalo/metabolismo , Genoma Humano , Proteínas de Choque Térmico/genética , Doença de Huntington/epidemiologia , Doença de Huntington/genética , Fatores de Transcrição/genética , Idade de Início , Éxons , Genômica , Proteínas de Choque Térmico/metabolismo , Humanos , Íntrons , Dados de Sequência Molecular , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Fatores de Transcrição/metabolismo
20.
Int J Tryptophan Res ; 17: 11786469241266312, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39092002

RESUMO

Tryptophan is an essential amino acid and plays an important role in several metabolic processes relevant for the human health. As the main metabolic pathway for tryptophan along the kynurenine axis is involved in inflammatory responses, changed metabolite levels can be used to monitor inflammatory diseases such as ulcerative colitis. As a progenitor of serotonin, altered tryptophan levels have been related to several neurogenerative diseases as well as depression or anxiety. While tryptophan concentrations are commonly evaluated in serum, a non-invasive detection approach using saliva might offer significant advantages, especially during long-term treatments of patients or elderly. In order to estimate whether active transport processes for tryptophan might contribute to a potential correlation between blood and saliva tryptophan concentrations, we investigated tryptophan's transport across an established oral mucosa in vitro model. Interestingly, treatment with tryptophan revealed a concentration dependent secretion of tryptophan and the presence of a saturable transporter while transport studies with deuterated tryptophan displayed increased permeability from the saliva to the blood compartment. Protein analysis demonstrated a distinct expression of L-type amino acid transporter 1 (LAT1), the major transporter for tryptophan, and exposure to inhibitors (2 -amino-2-norbornanecarboxylic acid (BCH), L-leucine) led to increased tryptophan levels on the saliva side. Additionally, exposure to tryptophan in equilibrium studies resulted in a regulation of LAT1 at the mRNA level. The data collected in this study suggest the participation of active transport mechanisms for tryptophan across the oral mucosa epithelium. Future studies should investigate the transport of tryptophan across salivary gland epithelia in order to enable a comprehensive understanding of tryptophan exchange at the blood-saliva barrier.

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