| Create a free account, build a dictionary with saved terms to re-use later! |
(4 coded questions)  |
Show articles that do not have abstracts
|
| Humans or Animals | | Humans Animals
| | | Ages | | All Infant: birth-23 months All Child: 0-18 years All Adult: 19+ years Newborn: birth-1 month Infant: 1-23 months Preschool Child: 2-5 years Child: 6-12 years Adolescent: 13-18 years Adult: 19-44 years Middle Aged: 45-64 years Middle Aged + Aged: 45+ years Aged: 65+ years 80 and over: 80+ years Undetermined
| | | Type of Article | | Clinical Trial Editorial Letter Meta-Analysis Practice Guideline Randomized Controlled Trial Review Addresses Bibliography Biography Case Reports Classical Article Clinical Conference Clinical Trial, Phase I Clinical Trial, Phase II Clinical Trial, Phase III Clinical Trial, Phase IV Comment Comparative Study Consensus Development Conference Consensus Development Conference, NIH Controlled Clinical Trial Corrected and Republished Article Dictionary Directory Duplicate Publication English Abstract Evaluation Studies Festschrift Government Publications Guideline Historical Article Interview In Vitro Journal Article Lectures Legal Cases Legislation Multicenter Study News Newspaper Article Overall Patient Education Handout Periodical Index Published Erratum Retracted Publication Research Support, N.I.H., Extramural Research Support, N.I.H., Intramural Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Research Support, U.S. Gov't, P.H.S. Retraction of Publication Scientific Integrity Review Support of Research Technical Report Twin Study Validation Studies Not a Primary Study or Review Unknown Primary Study Case Series Case Control Cohort Study Observational Study Qualitative Research CBA or ITS Registry Double Blind Controlled before after study Quasi-randomized trial Simple before after study Cluster-RCT Non-Randomized Study Report Book Book chapter Dissertation Conference procedings Secondary Research Not RCT
| | | Language | | English French German Italian Japanese Russian Spanish Afrikaans Albanian Unknown Arabic Armenian Azerbaijani Bosnian Bulgarian Catalan Chinese Croatian Czech Danish Dutch Esperanto Estonian Finnish Georgian Greek, Modern Hebrew Hindi Hungarian Icelandic Indonesian Kinyarwanda Korean Latin Latvian Lithuanian Macedonian Malay Malayalam Maori Multiple Languages Norwegian Persian Polish Portuguese Pushto Romanian Sanskrit Scottish gaelic Serbian Slovak Slovenian Swedish Thai Turkish Ukrainian Vietnamese Not English Not French
| |
|
(1-25 of 11,643) |
Sort By:
|
Took: 1.677 seconds to search 17,750,454 |
Matthias W Lorenz,Nina Thoelen,Nadine Loesel,Christian Lienerth,Marilen Gonzalez,Marek Humpich,Waltraud Roelz,Florian Dvorak,Matthias Sitzer Cerebral autoregulation is an important pathophysiological and prognostic parameter for a variety of neurologic conditions. It can be assessed quickly and safely using transcranial Doppler sonography (TCD). In elderly patients, poor insonation conditions decrease the number of examinable patients a... ( view more )nd can cause a systematic bias in autoregulation parameters. The aim of this study was to investigate whether a constant infusion of an ultrasound contrast agent (Levovist((R))) can counteract these effects. We examined two cohorts of unselected neurologic patients. In 45 patients with good insonation windows (cohort 1), we used a thin aluminium foil between the skin and the TCD probe to artificially decrease the insonation quality. We determined two parameters of cerebral autoregulation (phase difference [PD] and a cross-correlation coefficient [Mx]) in native patients, with aluminium foil and with aluminium foil and a constant infusion of Levovist. In 30 patients with poor insonation windows (cohort 2), we measured the autoregulation twice, with and without an infusion of Levovist, to assess the reproducibility of the autoregulation parameters. In cohort 1, the foil model significantly decreased the Doppler signal quality, i.e., the mean spectrum energy decreased from 33.9 +/- 2.7 dB to 26.3 +/- 2.4 dB (p < 0.001). This introduced a significant bias to all autoregulation parameters (PD: decreased from 38.2 +/- 10.0 degrees to 27.9 +/- 12.5 degrees (p < 0.001); Mx: decreased from 0.308 +/- 0.170 to 0.254 +/- 0.162 (p < 0.01)). Both effects were compensated largely by a constant infusion of Levovist (300 mg/min). In cohort 2, infusion of the contrast agent at the same rate increased insonation quality, too, but to a lesser degree (27.4 +/- 2.4 dB to 32.0 +/- 3.7 dB, p < 0.001). This smaller increase did not cause a significant change in the autoregulation parameters, but the reproducibility of the PD was significantly improved (intraclass coefficient coefficient [ICC] 0.76, 95% confidence interval [0.59-0.87] in native poor bone window compared with ICC 0.90, 95% confidence interval [0.81-0.95] with infusion of the contrast agent). Our data show that constant infusion of an ultrasound contrast agent during the assessment of cerebral autoregulation can avoid potential bias introduced by poor insonation conditions. Furthermore, infusion of the contrast agent can improve reproducibility and contribute to the credibility of autoregulation assessment in the elderly. (E-mail: matthias.lorenz@em.uni-frankfurt.de). ( view less ) Daniel Becker,Matthias Selbach,Claudia Rollenhagen,Matthias Ballmaier,Thomas F Meyer,Matthias Mann,Dirk Bumann New antibiotics are urgently needed to control infectious diseases. Metabolic enzymes could represent attractive targets for such antibiotics, but in vivo target validation is largely lacking. Here we have obtained in vivo information about over 700 Salmonella enterica enzymes from network analysis... ( view more ) of mutant phenotypes, genome comparisons and Salmonella proteomes from infected mice. Over 400 of these enzymes are non-essential for Salmonella virulence, reflecting extensive metabolic redundancies and access to surprisingly diverse host nutrients. The essential enzymes identified were almost exclusively associated with a small subgroup of pathways, enabling us to perform a nearly exhaustive screen. Sixty-four enzymes identified as essential in Salmonella are conserved in other important human pathogens, but almost all belong to metabolic pathways that are inhibited by current antibiotics or that have previously been considered for antimicrobial development. Our comprehensive in vivo analysis thus suggests a shortage of new metabolic targets for broad-spectrum antibiotics, and draws attention to some previously known but unexploited targets. ( view less ) Matthias Scheibitz,Michael Bolte,Jan W Bats,H-Wolfram Lerner,Israel Nowik,Rolfe H Herber,Andreas Krapp,Matthias Lein,Max C Holthausen,Matthias Wagner A comparison of the molecular structures of mono-, di- and tetraborylated ferrocenes [Fc{B(R(1))(R(2))}] (R(1)/R(2)=Br/Br, Br/Fc, Br/Me, Me/Me, Me/OH, OMe/OMe), 1,1'-[fc{B(R(1))(R(2))}(2)] (R(1)/R(2)=Br/Br, Br/Me, OMe/OMe), and 1,1',3,3'-[Fe{C(5)H(3)(BMe(2))(2)}(2)] revealed the boryl substituent(s... ( view more )) to be bent out of the Cp ring plane towards the iron center. The corresponding dip angle alpha* decreases with decreasing Lewis acidity of the boron atom and with increasing degree of borylation at the ferrocene core. This trend is well reproduced by DFT calculations (including [FcBH(2)], not yet accessible experimentally). A Bader analysis of the electron density topology of [FcBH(2)] (alpha*=26.5 degrees ; BP86/TZVP) clearly showed that there is no direct iron-boron bonding in this compound. Instead, strongly delocalized orbital interactions have been identified that involve the boron p orbital, C(ipso) of the adjacent Cp ring, d orbitals at iron, and a through-space interaction with the second Cp ring. A second important factor is attractive electrostatic interactions, which are enhanced upon ligand bending. Cyclic voltammetric measurements on the series [FcBMe(2)], 1,1'-[fc(BMe(2))(2)], and 1,1',3,3'-[Fe{C(5)H(3)(BMe(2))(2)}(2)] indicate a substantial anodic shift in the oxidation potential of the central iron atom upon introduction of BMe(2) substituents. Addition of 4-dimethylaminopyridine (DMAP) does not just counterbalance this effect, but leads to a cathodic shift of the Fe(II)/Fe(III) redox transition far beyond the half-wave potential of parent ferrocene. In the Mossbauer spectra, a continuous decrease in the quadrupole splitting (QS) is observed upon going from parent ferrocene to [FcBMe(2)], to 1,1'-[fc(BMe(2))(2)], and to 1,1',3,3'-[Fe{C(5)H(3)(BMe(2))(2)}(2)]. In contrast, no significant differences are found between the QS values of ferrocene, [Fc(BMe(2)-DMAP)], and 1,1'-[fc(BMe(2)-DMAP)(2)]. ( view less ) Matthias Hannig,Matthias Fiebiger,Matthias Güntzer,Angela Döbert,Ralf Zimehl,Yuriy Nekrashevych Salivary pellicle, as previously investigated, protects the enamel surface after certain processes of maturation against the influence of acidic agents. The aim of the present study was to investigate the protective effect of the short-term salivary pellicle formed in situ over periods of 3, 60 and... ( view more ) 120 min. Six human volunteers used intraoral acrylic splints with bovine enamel samples fixed at the buccal and palatal sites of the maxillary first molars and second premolars. Enamel specimens (n = 252) with and without pellicle were immersed for 60 s in 1.0% citric acid solution under agitation. Knoop surface hardness (KHN) of uneroded polished enamel was measured as a baseline and estimated immediately after erosive treatment reflecting the microhardness loss (DeltaKHN). The amounts of calcium dissolved from the eroded enamel surface were analysed by atomic absorption spectroscopy and scored in mg/l per 10 mm2 of enamel surface area. In addition, the scanning electron microscope was used for the micromorphological examination of the erosive alterations of the enamel surface. The average microhardness loss values after erosion of the enamel samples with buccally/palatally formed pellicle layers were measured as 139.1/144.9 DeltaKHN for 3 min pellicle, 145.9/146.9 DeltaKHN for 60 min pellicle and 141.7/138.6 DeltaKHN for 120 min pellicle. Calcium release values from the specimens with buccal/palatal pellicles were amounted to 15.0/14.9, 16.5/15.9 and 15.3/17.4 mg/l per 10 mm2 for 3, 60 and 120 min-old pellicles, respectively. No significant differences were related to the pellicle formation time and intraoral site (buccal or palatal) in all tested series (ANOVA, P < 0.05). However, significant protection of the enamel surface provided by the pellicle layer was observed on all pellicle-covered surfaces if compared to the non-covered enamel samples (calcium release: 25.6 mg/l per 10 mm2; microhardness loss 187.0 DeltaKHN). These data were in accordance with the morphologic alterations caused by citric acid on the pellicle-covered and pellicle non-covered specimens. It could be concluded that salivary pellicle formed in situ within a period of 3 min offers protection of enamel against citric acid. However, pellicle does not completely inhibit the erosive action of citric acid under the conditions of the present study. ( view less ) Matthias Kappler,Matthias Bache,Frank Bartel,Matthias Kotzsch,Matti Panian,Peter Würl,Karen Blümke,Hannelore Schmidt,Axel Meye,Helge Taubert Survivin, a member of the inhibitors-of-apoptosis gene family, is overexpressed in many tumor types. Survivin is a prognostic marker of soft-tissue sarcomas, but the downregulation of survivin expression and the possible dependency of survivin downregulation on p53 in these tumors have not been inv... ( view more )estigated. Therefore, we applied small interfering RNA (siRNA) to knock down the expression of survivin in five human sarcoma cell lines with wild-type or mutant p53 alleles. Compared with survivin mRNA expression in the nonsense siRNA-treated sarcoma cell lines, expression after treatment with survivin-specific siRNA was reduced by 73-88%; survivin protein expression was reduced by 52-81%. This finding was coupled with a reduction in clonogenic survival ranging from 65-86%. However, less than 10% of cells treated with survivin-specific siRNA underwent apoptosis. Cell-cycle and morphologic analyses showed that after a dramatic increase in the number of treated cells in the G2/M phase, some of the cells became polyploid; this result indicates that mitosis of a substantial number of treated cells was incomplete. Our findings suggest that survivin-specific siRNA could be a selective treatment to kill sarcoma cells regardless of the presence or absence of wild-type p53 alleles. ( view less ) Matthias Kappler,Matthias Kotzsch,Frank Bartel,Susanne Füssel,Christine Lautenschläger,Uta Schmidt,Peter Würl,Matthias Bache,Hannelore Schmidt,Helge Taubert,Axel Meye PURPOSE: Survivin is a member of the inhibitor-of-apoptosis gene family and is known to be overexpressed in a number of tumor types. The aim of this study was to evaluate the prognostic value of survivin protein expression in tumor tissue extracts in a group of well-characterized soft-tissue sarcom... ( view more )a (STS) patients. EXPERIMENTAL DESIGN: In this investigation, malignant tissue samples from 63 STS patients as well as from a panel of tumor cell lines were investigated, with nonmalignant tissues serving as controls. The survivin protein level was quantified by a novel ELISA and by Western blot analysis. Results obtained by both methods were compared with clinicopathological parameters regarding tumor grade and tumor entity, and they were then correlated to survival in a multivariate Cox regression model. RESULTS: High survivin levels were detected by ELISA and Western blot analysis in tumor tissue extracts and in lysates of tumor cell lines. None or only weak expression of survivin protein was found in nonmalignant cells and tissues. When comparing survivin values obtained by ELISA or Western blot, we found a significant correlation between both methods (P = 0.013, Pearson test). Our findings revealed that, in multivariate Cox regression analyses, survivin levels measured by ELISA and Western blot were significantly associated with tumor-related death in STS patients (P = 0.001, RR = 19.8, and P = 0.004, RR = 5.1, respectively). However, in a direct comparison of both survivin protein detection assays, we found a higher sensitivity and a stronger correlation to prognosis in survivin ELISA as compared with the Western blot assays. Furthermore, a higher tumor grade and more aggressive STS entity showed an elevated survivin protein expression level. CONCLUSION: Altogether, an elevated survivin content in tumor tissue extracts has a significant and independent negative predictive value on the survival-rate of STS patients. This finding corresponds well to data obtained for the mRNA level of survivin, as shown previously (M. Kappler et al., Int. J. Cancer, 95: 360-363, 2001). ( view less ) Marion Kixmöller,Matthias Ritzmann,Matthias Eddicks,Armin Saalmüller,Knut Elbers,Vicky Fachinger The effects of a single-dose recombinant Porcine circovirus type 2 (PCV2) open reading frame 2 (ORF2) subunit vaccine were studied in a post-weaning multisystemic wasting syndrome (PMWS)-affected pig herd. A total of 1519 3-week-old piglets were allocated randomly into two treatment groups and eith... ( view more )er vaccinated against PCV2 or treated with a placebo. Study animals were followed from the time of vaccination until the end of finishing. Onset of PCV2 viraemia and clinical signs of PMWS (wasting, cough, dyspnoea, pallor and lethargy) were observed when animals were approximately 9-10 weeks old. Compared to placebo-treated animals, vaccinated animals had a significantly reduced PCV2 viral load and duration of viraemia (p<0.0001). This reduction in viraemia was not affected by the level of maternal anti-PCV2 antibodies present at the time of vaccination. During the period of viraemia (10-26 weeks of age) vaccinated animals exhibited a 53% reduction in mortality rate (p=0.0010), a 4.84kg higher body weight gain (p<0.0001) and a significant reduction in clinical signs (p=0.0004). Furthermore, lung samples of vaccinated animals had a considerably reduced number of co-infections with PRRSV and Mycoplasma hyorhinis than lung samples of placebo-treated animals. These data indicate that vaccination against PCV2 alone protects pigs from clinical signs and co-infections associated with PMWS. ( view less ) Joon-Keun Park,Natalia Ronkina,Andreas Höft,Corinna Prohl,Jan Menne,Matthias Gaestel,Hermann Haller,Matthias Meier It is supposed that some stress-induced heat shock proteins (Hsps) are regulated through e.g. stimulation of the p38MAPK/MK(MAPKAP)-2 signalling pathway. It has been postulated from in vitro experiments that phosphorylation of Hsp25(rodents)/Hsp27(human), the major phosphorylation substrate of MK2,... ( view more ) is responsible for mesangial contractility and glomerular hyperfiltration in the diabetic kidney. To verify this hypothesis in vivo we studied the renal function of nondiabetic and streptozotocin (STZ)-induced, diabetic MK2(-/-) mice in comparison to wild-type (WT) control mice. Following 8 weeks of hyperglycaemia, light microscopy showed increased glomerulosclerosis and tubulointerstitial renal fibrosis in both diabetic study groups. Protein analysis demonstrated that Hsp25 phosphorylation is stimulated upon high-glucose condition but inhibited in the diabetic MK2(-/-) mice. However, we found the kidney-body weight ratio significantly increased in diabetic WT and MK2(-/-) mice. No difference regarding the increased expression of the extracellular matrix proteins and TGF-beta1 between both diabetic study groups was observed. Importantly, diabetic MK2(-/-) mice showed no protection against renal hyperfiltration in the diabetic state and the development of diabetic albuminuria. Although activation of p38MAPK has been previously shown in diabetes mellitus, our results indicate that blockade of the downstream MK2/Hsp25 signalling pathway does not interfere with the development of early diabetic nephropathy. ( view less ) Olga A Malysheva,Matthias Wahle,Ulf Wagner,Matthias Pierer,Sybille Arnold,Holm Häntzschel,Cristoph G O Baerwald OBJECTIVE: To assess the incidence and severity of disease modifying antirheumatic drug (DMARD)-induced adverse effects (AE) in patients with rheumatoid arthritis (RA) taking/not taking glucocorticoids (GC). More specifically, we tested whether GC can prolong the survival time of DMARD in patients ... ( view more )receiving combination therapy. METHODS: In a retrospective study of 154 patients with RA, data were examined for DMARD therapy and duration of low-dose GC ((3/4) 7.5 mg prednisone equivalent/day). Patients were followed for 2-62 months, and AE were graded following WHO criteria. RESULTS: GC therapy significantly increased the duration of therapy with sulfasalazine (SSZ) from 10.4 +/- 2.3 to 22.5 +/- 1.9 months and for methotrexate (MTX) from 21.8 +/- 2.9 to 43.3 +/- 2.7 months. Stratifying the withdrawal of DMARD for occurrence of AE and loss of efficacy revealed that GC comedication significantly increased the time until AE for users of MTX (3.0 +/- 0.6 vs 18.8 +/- 1.3 mo; p < 0.05), hydroxychloroquine (HCQ; 34.5 +/- 4.6 vs 54.4 +/- 5.1 mo; p < 0.05), and gold (6.6 +/- 0.9 vs 10.5 +/- 0.9 mo; p < 0.05). In patients taking SSZ the time until cessation due to loss of efficacy increased significantly under GC comedication (16.8 +/- 1.2 vs 31.3 +/- 2.9 mo; p < 0.05). However, in patients taking azathioprine (AZA) the duration of therapy decreased from 44.4 +/- 2.6 to 22.3 +/- 1.6 months under GC due to both time until AE and loss of efficacy. Patients under comedication of MTX + GC, HCQ + GC, and AZA + GC experienced significantly more AE compared to the respective DMARD monotherapy. A highly significant reduction was observed in the frequency of erosive RA in patients with GC comedication (n = 30; 49.1%) compared to patients without low-dose GC (n = 81, 80.4%; OR 4.05, 95% CI 1.91-8.66, p < 0.0001). CONCLUSION: Low-dose GC retard radiological progression of RA and exhibit a differential effect on survival of DMARD and degree of AE due to DMARD. Further studies are warranted to address safety and interactions of chronic low-dose GC in RA patients treated with DMARD. ( view less ) STAR Consortium ,Kathrin Saar,Alfred Beck,Marie-Thérèse Bihoreau,Ewan Birney,Denise Brocklebank,Yuan Chen,Edwin Cuppen,Stephanie Demonchy,Joaquin Dopazo,Paul Flicek,Mario Foglio,Asao Fujiyama,Ivo G Gut,Dominique Gauguier,Roderic Guigo,Victor Guryev,Matthias Heinig,Oliver Hummel,Niels Jahn,Sven Klages,Vladimir Kren,Michael Kube,Heiner Kuhl,Takashi Kuramoto,Yoko Kuroki,Doris Lechner,Young-Ae Lee,Nuria Lopez-Bigas,G Mark Lathrop,Tomoji Mashimo,Ignacio Medina,Richard Mott,Giannino Patone,Jeanne-Antide Perrier-Cornet,Matthias Platzer,Michal Pravenec,Richard Reinhardt,Yoshiyuki Sakaki,Markus Schilhabel,Herbert Schulz,Tadao Serikawa,Medya Shikhagaie,Shouji Tatsumoto,Stefan Taudien,Atsushi Toyoda,Birger Voigt,Diana Zelenika,Heike Zimdahl,Norbert Hubner The laboratory rat is one of the most extensively studied model organisms. Inbred laboratory rat strains originated from limited Rattus norvegicus founder populations, and the inherited genetic variation provides an excellent resource for the correlation of genotype to phenotype. Here, we report a ... ( view more )survey of genetic variation based on almost 3 million newly identified SNPs. We obtained accurate and complete genotypes for a subset of 20,238 SNPs across 167 distinct inbred rat strains, two rat recombinant inbred panels and an F2 intercross. Using 81% of these SNPs, we constructed high-density genetic maps, creating a large dataset of fully characterized SNPs for disease gene mapping. Our data characterize the population structure and illustrate the degree of linkage disequilibrium. We provide a detailed SNP map and demonstrate its utility for mapping of quantitative trait loci. This community resource is openly available and augments the genetic tools for this workhorse of physiological studies. ( view less ) Stijntje D Roes,Grigorios Korosoglou,Michael Schär,Jos J Westenberg,Matthias J P van Osch,Albert de Roos,Matthias Stuber PURPOSE: To evaluate the effect of a real-time adaptive trigger delay on image quality to correct for heart rate variability in 3D whole-heart coronary MR angiography (MRA). MATERIALS AND METHODS: Twelve healthy adults underwent 3D whole-heart coronary MRA with and without the use of an adaptive tr... ( view more )igger delay. The moment of minimal coronary artery motion was visually determined on a high temporal resolution MRI. Throughout the scan performed without adaptive trigger delay, trigger delay was kept constant, whereas during the scan performed with adaptive trigger delay, trigger delay was continuously updated after each RR-interval using physiological modeling. Signal-to-noise, contrast-to-noise, vessel length, vessel sharpness, and subjective image quality were compared in a blinded manner. RESULTS: Vessel sharpness improved significantly for the middle segment of the right coronary artery (RCA) with the use of the adaptive trigger delay (52.3 +/- 7.1% versus 48.9 +/- 7.9%, P = 0.026). Subjective image quality was significantly better in the middle segments of the RCA and left anterior descending artery (LAD) when the scan was performed with adaptive trigger delay compared to constant trigger delay. CONCLUSION: Our results demonstrate that the use of an adaptive trigger delay to correct for heart rate variability improves image quality mainly in the middle segments of the RCA and LAD. ( view less ) Xandra Volkmann,Matthias Anstaett,Johannes Hadem,Penelope Stiefel,Matthias J Bahr,Frank Lehner,Michael P Manns,Klaus Schulze-Osthoff,Heike Bantel Acute liver failure (ALF) has various causes and is characterized by rapid hepatocyte dysfunction with development of encephalopathy in the absence of preexisting liver disease. Whereas most patients require liver transplantation to prevent the high mortality, some patients recover spontaneously an... ( view more )d show complete liver regeneration. Because of the low incidence of ALF, however, the molecular mechanisms of liver dysfunction and regeneration are largely unknown. In this study, we investigated the role of apoptosis and caspases in 70 ALF patients using novel biomarkers that allow the detection of caspase activation in serum samples. Compared with healthy individuals, activation of caspases was strongly enhanced in ALF patients. Interestingly, patients with spontaneous recovery from ALF revealed a significantly higher activation of caspases than patients that required transplantation or died, although in the latter patients extensive DNA fragmentation and signs of nonapoptotic cell death were observed. In the spontaneous survivors, increased caspase activation was accompanied by elevated levels of tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6), important cytokines involved in liver regeneration. Conclusion: Our data suggest that caspase activation and apoptosis are involved in ALF of patients with spontaneous recovery, whereas caspase-independent cell death might be more relevant in irreversible forms of liver failure. These findings might be important for therapeutic options of ALF but also suggest that measurement of caspase activation might be of prognostic value to predict the outcome of acute liver failure. ( view less ) Matthias Hild,Matthias Krause,Iris Riemann,Pedro Mestres,Sergey Toropygin,Ursula Löw,Karin Brückner,Berthold Seitz,Christian Jonescu-Cuypers,Karsten KönigPURPOSE: To investigate retinal imaging and ablation using femtosecond laser pulses. MATERIALS AND METHODS: Two non-amplified near-infrared femtosecond lasers were used to irradiate porcine retinal specimens in vitro. The lasers were used for tissue removal as well as multiphoton laser scanning mic... ( view more )roscopy. RESULTS: Ablation of the nerve fiber layer was performed at pulse energies of 1.0 nJ to 3.9 nJ. Control laser scanning images were acquired within seconds after irradiation. Specimens were additionally investigated with electron microscopy. CONCLUSIONS: Non-amplified femtosecond lasers may allow precise surgery controlled by fast high-resolution imaging of the target. ( view less ) Anne Fougerat,Stéphanie Gayral,Pierre Gourdy,Alexia Schambourg,Thomas Rückle,Matthias K Schwarz,Christian Rommel,Emilio Hirsch,Jean-François Arnal,Jean-Pierre Salles,Bertrand Perret,Monique Breton-Douillon,Matthias P Wymann,Muriel Laffargue BACKGROUND: The role of inflammation at all stages of the atherosclerotic process has become an active area of investigation, and there is a notable quest for novel and innovative drugs for the treatment of atherosclerosis. The lipid kinase phosphoinositide 3-kinase-gamma (PI3Kgamma) is thought to ... ( view more )be a key player in various inflammatory, autoimmune, and allergic processes. These properties and the expression of PI3Kgamma in the cardiovascular system suggest that PI3Kgamma plays a role in atherosclerosis. METHODS AND RESULTS: Here, we demonstrate that a specific PI3Kgamma inhibitor (AS605240) is effective in murine models of established atherosclerosis. Intraperitoneal administration of AS605240 (10 mg/kg daily) significantly decreased early atherosclerotic lesions in apolipoprotein E-deficient mice and attenuated advanced atherosclerosis in low-density lipoprotein receptor-deficient mice. Furthermore, PI3Kgamma levels were elevated in both human and murine atherosclerotic lesions. Comparison of low-density lipoprotein receptor-deficient mice transplanted with wild-type or PI3Kgamma-deficient bone marrow demonstrated that functional PI3Kgamma in the hematopoietic lineage is required for atherosclerotic progression. Alleviation of atherosclerosis by targeting of PI3Kgamma activity was accompanied by decreased macrophage and T-cell infiltration, as well as increased plaque stabilization. CONCLUSIONS: These data identify PI3Kgamma as a new target in atherosclerosis with the potential to modulate multiple stages of atherosclerotic lesion formation, such as fatty streak constitution, cellular composition, and final fibrous cap establishment. ( view less ) Yu Zhang,Sohee Kwon,Teppei Yamaguchi,Fabien Cubizolles,Sophie Rousseaux,Michaela Kneissel,Chun Cao,Na Li,Hwei-Ling Cheng,Katrin Chua,David Lombard,Adam Mizeracki,Gabriele Matthias,Frederick W Alt,Saadi Khochbin,Patrick Matthias Posttranslational modifications play important roles in regulating protein structure and function. Histone deacetylase 6 (HDAC6) is a mostly cytoplasmic class II HDAC, which has a unique structure with two catalytic domains and a domain binding ubiquitin with high affinity. This enzyme was recently... ( view more ) identified as a multisubstrate protein deacetylase that can act on acetylated histone tails, alpha-tubulin and Hsp90. To investigate the in vivo functions of HDAC6 and the relevance of tubulin acetylation/deacetylation, we targeted the HDAC6 gene by homologous recombination in embryonic stem cells and generated knockout mice. HDAC6-deficient mice are viable and fertile and show hyperacetylated tubulin in most tissues. The highest level of expression of HDAC6 is seen in the testis, yet development and function of this organ are normal in the absence of HDAC6. Likewise, lymphoid development is normal, but the immune response is moderately affected. Furthermore, the lack of HDAC6 results in a small increase in cancellous bone mineral density, indicating that this deacetylase plays a minor role in bone biology. HDAC6-deficient mouse embryonic fibroblasts show apparently normal microtubule organization and stability and also show increased Hsp90 acetylation correlating with impaired Hsp90 function. Collectively, these data demonstrate that mice survive well without HDAC6 and that tubulin hyperacetylation is not detrimental to normal mammalian development. ( view less ) Sergey Toropygin,Matthias Krause,Iris Riemann,Matthias Hild,Pedro Mestres,Berthold Seitz,Elena Khurieva,Klaus W Ruprecht,Ursula Löw,Zisis Gatzioufas,Karsten KönigPURPOSE: To investigate intravenous femtosecond laser surgery in models of branch retinal vein occlusion. MATERIALS AND METHODS: Non-amplified near infrared femtosecond laser was used to ablate polyamide sutures and human hairs inserted into the vascular lumina of porcine retinal veins in vitro. Sp... ( view more )ecimens were subjected to multiphoton laser scanning microscopy and electron microscopy. RESULTS: Regular laser cuts within sutures and hairs were detected with laser microscopy and electron microscopy. Neither laser microscopy nor histology revealed collateral damage of the vascular wall. CONCLUSIONS: Non-amplified femtosecond lasers may allow precise atraumatic non-contact intravenous retinal surgery controlled by high-resolution imaging of the target. ( view less ) Philipp Latzin,Maya Fehling,Adolf Bauernfeind,Dietrich Reinhardt,Matthias Kappler,Matthias Griese BACKGROUND: Cystic fibrosis (CF) is characterized by chronic bacterial broncho-pulmonary infection. Although intravenous (i.v.) antibiotic therapy is regarded as standard treatment in CF, only few randomised trials comparing different antibiotic compounds exist. METHODS: We report on a prospective ... ( view more )multicenter interventional trial of i.v. meropenem (120 mg/kg/day) or i.v. ceftazidime (200-400 mg/kg/day), each administered together with i.v. tobramycin (9-12 mg/kg/day). Outcome measures were changes in lung function, microbiological sputum burden and blood inflammatory marker. Liver and renal function values were measured to assess safety. RESULTS: One hundred eighteen patients (59/59) were included into the study with the following indications: first infection of P. aeruginosa (n=6), acute pulmonary exacerbation (n=34) and suppression therapy of chronic P. aeruginosa colonization (n=78). Both treatments improved lung function measures, bacterial sputum burden and CRP levels with no differences between treatment groups observed. A significant higher elevation for alkaline phosphatase (p<0.0001) was observed for patients in the meropenem/tobramycin group. CONCLUSIONS: i.v. antibiotic therapy in CF patients with meropenem/tobramycin is as effective as with ceftazidime/tobramycin regarding lung function, microbiological sputum burden and systemic inflammatory status. Hepato-biliary function should be monitored carefully during i.v. treatment, possibly important in CF patients with pre-existing liver disease. ( view less ) Kathrin Dellas,Matthias Bache,Steffi U Pigorsch,Helge Taubert,Matthias Kappler,Daniel Holzapfel,Ester Zorn,Hans-Juergen Holzhausen,Gabriele Haensgen PURPOSE: To investigate the relationship between the hypoxia-inducible factor-(HIF-)1alpha expression in tumor tissue, tumor oxygenation and hemoglobin levels in patients with advanced cervical cancers prior to radiotherapy and the effect on clinical outcome. PATIENTS AND METHODS: The investigation... ( view more ) included 44 patients who underwent definitive radiotherapy for advanced cervical cancers between May 1995 and March 1999. Tumor biopsies were taken prior to treatment, and HIF-1alpha expression was determined by immunohistochemistry. In the same tumor area, tumor tissue oxygenation (pO2) was measured using the Eppendorf device. RESULTS: The 5-year cancer-specific survival of all patients was 60%. Twelve of 44 tumor specimens were HIF-1alpha-negative with a significantly better 5-year survival (92 +/- 8%) versus 32 patients who were HIF-1alpha-positive (45 +/- 10%; p < 0.02). There was no correlation between HIF-1alpha expression and tumor oxygenation (p = 0.57 both for pO2 median and hypoxic fraction < 5 mmHg vs. HIF-1alpha expression). However, patients with hemoglobin levels < 11 g/dl showed elevated HIF-1alpha expression compared to patients with hemoglobin levels > 12.5 g/dl (p = 0.04). Furthermore, HIF-1alpha correlated with vascular endothelial growth factor expression (p = 0.002). In a multivariate Cox regression model, HIF-1alpha expression (relative risk [RR] = 7.5; p = 0.05) revealed an increased risk of tumor-related death. CONCLUSION: The study indicates, that endogenous tumor markers such as HIF-1alpha may serve as prognostic markers of clinical outcome concerning cervical cancer after primary radiotherapy. ( view less ) Tsvetomir Loukanov,Christian Sebening,Wolfgang Springer,Markus Khalil,Herbert E Ulmer,Siegfried Hagl,Matthias Karck,Matthias Gorenflo OBJECTIVE: Timing of the operation for exchange of right ventricular (RV) to pulmonary artery (PA) conduits is a matter of considerable debate. We aimed to study the course of right ventricular dimension in patients undergoing conduit exchange. PATIENTS AND METHODS: We retrospectively studied all p... ( view more )atients who underwent implantation and or replacement of RV/PA conduits during the time period between 1990 and 2005. Clinical and echocardiographic data were recorded as obtained at follow-up visits. RESULTS: A total of 229 (144 boys and 85 girls) underwent surgery for implantation and or replacement of RV/PA conduits during the study period. Patients were assigned to three age groups including 37 infants, 125 children aged 1-10 years and 67 patients more than 10 years of age. 185 pulmonary (81%) and 44 aortic homografts (19%) were implanted. Fifty-eight of these 185 patients (25%) required exchange of conduits after a median time of 6.4 (8 months-12 years) (median (range)). The follow-up was 7.55 (0.1-17) years. The survival of the patients after homograft change was 98%. Freedom from failure for aortic and pulmonary homografts at an interval of 10 years for all patients was 38.5% for aortic and 56.2% for pulmonary homografts (P = 0.018; Mann-Whitney). Age at conduit exchange (coefficient: -4.917; P < 0.001) and right ventricular end-diastolic dimension (RVDD) before conduit exchange (coefficient: 8.255; P < 0.001) were related to RVDD as measured by M-mode echocardiography at follow-up ("best subset" regression analysis; R squared = 0.746). RVDD decreased in 48/58 patients, remained unchanged in 8/58 and increased in 2/59 patients at follow-up. An increased RVDD was positively correlated to the duration of artificial ventilation after the operation for conduit exchange (R = 0.56; P < 0.001). CONCLUSIONS: Reoperation for exchange of degenerated conduits should be performed early to prevent the development of irreversible structural myocardial changes and persistence of right ventricular dilatation. ( view less ) Simon Grill,Simone Busenbender,Matthias Pfeiffer,Uwe Köhler,Matthias Mack Streptomyces davawensis synthesizes the antibiotic roseoflavin, one of the few known natural riboflavin analogs, and is roseoflavin resistant. It is thought that the endogenous flavokinase (EC 2.7.1.26)/flavin adenine dinucleotide (FAD) synthetase (EC 2.7.7.2) activities of roseoflavin-sensitive or... ( view more )ganisms are responsible for the antibiotic effect of roseoflavin, producing the inactive cofactors roseoflavin-5'-monophosphate (RoFMN) and roseoflavin adenine dinucleotide (RoFAD) from roseoflavin. To confirm this, the FAD-dependent Sus scrofa D-amino acid oxidase (EC 1.4.3.3) was tested with RoFAD as a cofactor and found to be inactive. It was hypothesized that a flavokinase/FAD synthetase (RibC) highly specific for riboflavin may be present in S. davawensis, which would not allow the formation of toxic RoFMN/RoFAD. The gene ribC from S. davawensis was cloned. RibC from S. davawensis was overproduced in Escherichia coli and purified. Analysis of the flavokinase activity of RibC revealed that the S. davawensis enzyme is not riboflavin specific (roseoflavin, kcat/Km = 1.7 10(-2) microM(-1) s(-1); riboflavin, kcat/Km = 7.5 10(-3) microM(-1) s(-1)). Similar results were obtained for RibC from the roseoflavin-sensitive bacterium Bacillus subtilis (roseoflavin, kcat/Km = 1.3 10(-2) microM(-1) s(-1); riboflavin, kcat/Km = 1.3 10(-2) microM(-1) s(-1)). Both RibC enzymes synthesized RoFAD and RoFMN. The functional expression of S. davawensis ribC did not confer roseoflavin resistance to a ribC-defective B. subtilis strain. ( view less ) Ronald Mai,Antje Reinstorf,Eckart Pilling,Matthias Hlawitschka,Roland Jung,Michael Gelinsky,Matthias Schneider,Richard Loukota,Wolfgang Pompe,Uwe Eckelt,Bernd Stadlinger OBJECTIVE: Calcium phosphates are clinically established as bone defect fillers. They have the capability of osseoconduction and are characterized by a slow resorption process. The present study evaluated the suitability of a newly developed calcium phosphate cement modified with collagen type I. S... ( view more )TUDY DESIGN: The modified cement paste was inserted in differently designed defects of 10 minipigs. Further, an alveolar ridge augmentation was performed, applying the cement paste. The cement hardened in situ during the operation, forming a hydroxyapatite collagen composite. Animals were sacrificed after 1, 3, 6, 12, and 18 months. The tissue integration and resorption process was then evaluated using nondecalcified microsections. All animals were evaluated for histology. RESULTS: The implanted material showed osseoconductive characteristics. Resorption started from the edge of the defect zone, and bone substitution followed rapidly. Twelve months after placement of the cement, complete remodeling was observed. CONCLUSION: It can be concluded that the applied hydroxyapatite-collagen cement composite shows good resorption and bone integration. ( view less ) Andreas Goette,Alicja Bukowska,Uwe Lendeckel,Michaela Erxleben,Matthias Hammwöhner,Denis Strugala,Jan Pfeiffenberger,Friedrich-Wilhelm Röhl,Christof Huth,Matthias P A Ebert,Helmut U Klein,Christoph Röcken BACKGROUND: Increased levels of inflammatory markers are predictors of thromboembolic events during atrial fibrillation (AF). Increased endocardial expression of adhesion molecules (ie, vascular cell adhesion molecule [VCAM] and intercellular adhesion molecule [ICAM]) could be an important link bet... ( view more )ween initiation of inflammatory and prothrombogenic mechanisms responsible for thrombus development at the atrial endocardium (endocardial remodeling). METHODS AND RESULTS: Tissue microarrays were used to screen right atrial tissue specimens obtained from 320 consecutive patients for differences in atrial expression of the prothrombogenic proteins VCAM-1, ICAM-1, thrombomodulin, plasminogen activator inhibitor-1, and von Willebrand factor. An in vitro organotypic human atrial tissue model and a pig model of rapid atrial pacing were used to determine the therapeutic impact of angiotensin II receptor blockade. Immunohistochemical analyses showed that all prothrombogenic proteins are expressed by endocardial cells. Using multivariable analysis, only the intensity of VCAM-1 expression was increased in patients with AF (P=0.03). Increased atrial VCAM-1 expression was confirmed by Western blotting in patients with persistent and paroxysmal AF (persistent AF 207+/-42% versus sinus rhythm 100+/-16%, P=0.028; paroxysmal AF 193+/-42%, P=0.024 versus sinus rhythm). In vitro pacing of ex vivo human atrial tissue slices confirmed that rapid activation causes VCAM-1 upregulation (mRNA and protein levels). Pacing-induced VCAM-1 expression was abolished by olmesartan. To confirm this finding in vivo, VCAM-1 expression was determined in 14 pigs after rapid atrial pacing (600 bpm). Atrial tachycardia caused an upregulation of VCAM-1 expression, which was prevented by irbesartan, consistent with the observed increase in plasma levels of angiotensin II. Alterations in the in vivo VCAM-1 expression were more pronounced in the left atrium (>5-fold compared with sham) than in the right atrium (3.5-fold compared with sham). CONCLUSIONS: AF and rapid atrial pacing both increase endocardial VCAM-1 expression, which can be attenuated by angiotensin II receptor blockade. This provides evidence that angiotensin II plays a pathophysiological role in prothrombotic endocardial remodeling. ( view less ) Wilko Weichert,Annika Röske,Volker Gekeler,Thomas Beckers,Matthias P A Ebert,Matthias Pross,Manfred Dietel,Carsten Denkert,Christoph Röcken BACKGROUND: Although histone deacetylases (HDACs) are known to have an important regulatory role in cancer cells, and HDAC inhibitors (HDIs) have entered late-phase clinical trials for the treatment of several cancers, little is known about the expression patterns of HDAC isoforms in tumours. We ai... ( view more )med to clarify these expression patterns and identify potential diagnostic and prognostic uses of selected class I HDAC isoforms in gastric cancer. METHODS: Tissue samples from a training cohort and a validation cohort of patients with gastric cancer from two German institutions were used for analyses. Tissue microarrays were generated from tumour tissue collected from patients in the training group, whereas tissue slides were used in the validation group. The tissues were scored for expression of class I HDAC isoforms 1, 2, and 3. Overall expression patterns (gHDAC) were grouped as being negative (all three isoforms negative), partially positive (one or two isoforms positive), or completely positive (all isoforms positive), and correlated with clinicopathological parameters and patient survival. The main endpoints were amount of expression of each of the three HDAC isoforms, patterns of expression of gHDAC, effect of metastasis on expression of HDAC and gHDAC, and overall survival according to HDAC expression patterns. FINDINGS: 2617 tissue microarray spots from 143 patients in the training cohort and 606 tissue slides from 150 patients in the validation cohort were studied. 52 of the 143 (36%) gastric tumours in the training cohort and 32 of the 150 (21%) gastric tumours in the validation cohort showed nuclear expression of all three HDAC isoforms. 60 (42%) of tumours in the training cohort and 65 (43%) in the validation cohort expressed one or two isoforms in the nuclei, whereas 31 (22%) of tumours in the training cohort and 53 (35%) in the validation cohort were scored negative for all three proteins. gHDAC expression in both cohorts was higher when lymph-node metastases were present (p=0.0175 for the training group and p=0.0242 for the validation group). Survival data were available for 49 patients in the training group and 123 patients in the validation group. In the validation cohort, 3-year survival was 44% (95% CI 34-57) in the HDAC1-negative group, 50% (39-64) in the HDAC2-negative group, and 48% (34-67) in the gHDAC-negative group. 3-year survival decreased to 21% (11-37) when HDAC1 was positive, 16% (9-31) when HDAC2 was positive, and 5% (1-31) when gHDAC (all isoforms) were positive. Those patients highly expressing one or two isoforms (the gHDAC-intermediate group) had an estimated 3-year survival of 40% (29-56). In multivariate analyses, high gHDAC and HDAC2 expression were associated with shorter survival in the training cohort (gHDAC: hazard ratio [HR] 4.15 [1.23-13.99], p=0.0250; HDAC2: HR 3.58 [1.36-9.44], p=0.0100) and in the validation cohort (gHDAC: HR 2.18 [1.19-4.01], p=0.0433; HDAC2: HR 1.72 [1.08-2.73], p=0.0225), independent of standard clinical predictors. INTERPRETATION: High HDAC expression is significantly associated with nodal spread and is an independent prognostic marker for gastric cancer. Additionally, we postulate that immunohistochemical detection of HDAC as a companion diagnostic method might predict treatment response to HDIs, thereby enabling selection of patients for this specific targeted treatment in gastric cancer. ( view less ) Julia Stieglmaier,Edwin Bremer,Christian Kellner,Tanja M Liebig,Bram ten Cate,Matthias Peipp,Hendrik Schulze-Koops,Matthias Pfeiffer,Hans-Jörg Bühring,Johann Greil,Fuat Oduncu,Bertold Emmerich,Georg H Fey,Wijnand Helfrich Although the treatment outcome of lymphoid malignancies has improved in recent years by the introduction of transplantation and antibody-based therapeutics, relapse remains a major problem. Therefore, new therapeutic options are urgently needed. One promising approach is the selective activation of... ( view more ) apoptosis in tumor cells by the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). This study investigated the pro-apoptotic potential of a novel TRAIL fusion protein designated scFvCD19:sTRAIL, consisting of a CD19-specific single-chain Fv antibody fragment (scFv) fused to the soluble extracellular domain of TRAIL (sTRAIL). Potent apoptosis was induced by scFvCD19:sTRAIL in several CD19-positive tumor cell lines, whereas normal blood cells remained unaffected. In mixed culture experiments, selective binding of scFvCD19:sTRAIL to CD19-positive cells resulted in strong induction of apoptosis in CD19-negative bystander tumor cells. Simultaneous treatment of CD19-positive cell lines with scFvCD19:sTRAIL and valproic acid (VPA) or Cyclosporin A induced strongly synergistic apoptosis. Treatment of patient-derived acute B-lymphoblastic leukemia (B-ALL) and chronic B-lymphocytic leukemia (B-CLL) cells resulted in strong tumoricidal activity that was further enhanced by combination with VPA. In addition, scFvCD19:sTRAIL prevented engraftment of human Nalm-6 cells in xenotransplanted NOD/Scid mice. The pre-clinical data presented here warrant further investigation of scFvCD19:sTRAIL as a potential new therapeutic agent for CD19-positive B-lineage malignancies. ( view less ) Raoul Arnold,Julia Ley-Zaporozhan,Sebastian Ley,Tsvetomir Loukanov,Christian Sebening,Johann-Baptist Kleber,Björn Goebel,Siegfried Hagl,Matthias Karck,Matthias Gorenflo BACKGROUND: We asked whether aortic valve replacement using a mechanical prosthesis would allow normalization of left ventricular function and structure in children and young adults. METHODS: We performed a clinical follow-up examination in 30 patients with aortic valve replacement at 25 years of a... ( view more )ge or younger, including conventional and tissue Doppler echocardiography and magnetic resonance imaging. RESULTS: Aortic valve replacement was performed at the median age of 14.3 years (range, 7.6 to 24.3 years) using a mechanical prosthesis (St. Jude Medical; median diameter, 23 mm; range, 17 to 27 mm). Indications were severe aortic stenosis in 6 of 30 patients, aortic regurgitation in 20 of 30 patients, or a combination of aortic stenosis and regurgitation (4 of 30 patients). Aortic valve replacement was a reoperation in 12 of 30 patients who primarily underwent aortic valvotomy at a median of 7.1 years (range, 1.0 to 11.3 years). In-hospital mortality was 0%. Follow-up was a median of 6 years (range, 1.2 to 14.5 years). Twenty-nine of 30 patients were in New York Heart Association functional class I without thromboembolic complications, cerebrovascular accidents, or major bleeding on oral anticoagulation. Left ventricular dilatation before aortic valve replacement was present in 20 of 30 patients but normalized in all but 4 patients on follow-up. Most patients showed a normal end-diastolic volume on magnetic resonance imaging, and 23 of 26 patients showed a normal left ventricular ejection fraction (median, 0.53; range, 0.33 to 0.75). Peak systolic strain of the left ventricular myocardium was a median of -13.3% (range, -0.5% to -31%), and was normal in 28 of 30 patients. CONCLUSIONS: Aortic valve replacement in children and young adults offers a good treatment option and may lead to normalization of left ventricular size and function in most patients. ( view less )
|
|
|