22 resultados para Ultrasound-assisted enzymatic hydrolysis

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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Since October 2011, the enzymatic lysis of Dupuytren's cord was introduced in Switzerland (Xiapex(®), Auxilium Pharmaceuticals, Pfizer). Here we present our first university experience and underline the major role of ultrasound during the injection. Between December 2011 and February 2013, 52 injections were performed to eliminate 43 Dupuytren's cords in 33 patients. The mean age of the patients was 64.4 ± 8.5 years. Complications were documented for each patient. Before, directly after and after a minimum of 6 months post-injection, the contracture of the treated joint was measured with use of a goniometer. The DASH score was evaluated after a minimum of 6 months and the patients were asked to subjectively evaluate the outcome of the treatment (very good, good, mild, poor) and whether they would reiterate it if necessary. Four skin defects, one lymphangitis, and one CRPS were responsible for a complication rate of 18%. There was no infection and no tendon rupture in the series. The mean MCP joint contracture was respectively 36.8 ± 27.4°, 3.5 ± 7.8° (gain of mobility compared to the preoperative situation 33.3°, P<0.001), and 8.4 ± 13.9° (gain 28.4°, P<0.001) respectively before, just after and at the long-term clinical control. The mean PIP joint contracture was respectively 36.5 ± 29.1°, 5.9 ± 6.7° (gain 30.6°, P<0.001), and 15.1 ± 13.8° (gain 21.4°, P<0.001) respectively before injection, just after and at the long-term clinical control. The DASH score decreased from 24 ± 14 to 7 ± 9 (P<0.001). Eighty-one per cent of the patients were satisfied or very satisfied of the treatment. All but two would reiterate the treatment if necessary. Ultrasound is able to target the injection of collagenase in order to reduce complications. The short-term results of this non-invasive therapy are very promising however comparison with conventional procedures is difficult as the long-term results are lacking.

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

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BACKGROUND In patients with acute pulmonary embolism, systemic thrombolysis improves right ventricular (RV) dilatation, is associated with major bleeding, and is withheld in many patients at risk. This multicenter randomized, controlled trial investigated whether ultrasound-assisted catheter-directed thrombolysis (USAT) is superior to anticoagulation alone in the reversal of RV dilatation in intermediate-risk patients. METHODS AND RESULTS Fifty-nine patients (63±14 years) with acute main or lower lobe pulmonary embolism and echocardiographic RV to left ventricular dimension (RV/LV) ratio ≥1.0 were randomized to receive unfractionated heparin and an USAT regimen of 10 to 20 mg recombinant tissue plasminogen activator over 15 hours (n=30; USAT group) or unfractionated heparin alone (n=29; heparin group). Primary outcome was the difference in the RV/LV ratio from baseline to 24 hours. Safety outcomes included death, major and minor bleeding, and recurrent venous thromboembolism at 90 days. In the USAT group, the mean RV/LV ratio was reduced from 1.28±0.19 at baseline to 0.99±0.17 at 24 hours (P<0.001); in the heparin group, mean RV/LV ratios were 1.20±0.14 and 1.17±0.20, respectively (P=0.31). The mean decrease in RV/LV ratio from baseline to 24 hours was 0.30±0.20 versus 0.03±0.16 (P<0.001), respectively. At 90 days, there was 1 death (in the heparin group), no major bleeding, 4 minor bleeding episodes (3 in the USAT group and 1 in the heparin group; P=0.61), and no recurrent venous thromboembolism. CONCLUSIONS In patients with pulmonary embolism at intermediate risk, a standardized USAT regimen was superior to anticoagulation with heparin alone in reversing RV dilatation at 24 hours, without an increase in bleeding complications. CLINICAL TRIAL REGISTRATION URL http://www.clinicaltrials.gov. Unique identifier: NCT01166997.

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Patients with ilio-femoral deep-vein thrombosis (DVT) are at high risk of developing the post-thrombotic syndrome (PTS). In comparison to anticoagulation therapy alone, extended venography-guided catheter-directed thrombolysis without routine stenting of venous stenosis in patients with ilio-femoral DVT is associated with an increased risk of bleeding and a moderate reduction of PTS. We performed a prospective single-centre study to investigate safety, patency and incidence of PTS in patients with acute ilio-femoral DVT treated with fixed-dose ultrasound-assisted catheter-directed thrombolysis (USAT; 20 mg rt-PA during 15 hours) followed by routing stenting of venous stenosis, defined as residual luminal narrowing >50%, absent antegrade flow, or presence of collateral flow at the site of suspected stenosis. A total of 87 patients (age 46 ± 21 years, 60% women) were included. At 15 hours, thrombolysis success ≥50% was achieved in 67 (77%) patients. Venous stenting (mean 1.9 ± 1.3 stents) was performed in 70 (80%) patients, with the common iliac vein as the most frequent stenting site (83%). One major (1%; 95% CI, 0-6%) and 6 minor bleedings (7%; 95%CI, 3-14%) occurred. Primary and secondary patency rates at 1 year were 87% (95% CI, 74-94%) and 96% (95% CI, 88-99%), respectively. At three months, 88% (95% CI, 78-94%) of patients were free from PTS according to the Villalta scale, with a similar rate at one year (94%, 95% CI, 81-99%). In conclusion, a fixed-dose USAT regimen followed by routine stenting of underlying venous stenosis in patients with ilio-femoral DVT was associated with a low bleeding rate, high patency rates, and a low incidence of PTS.

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Pulmonary embolism remains a common and potentially life-threatening disease. For patients with intermediate- and high-risk pulmonary embolism, catheter-based revascularization therapy has emerged as potential alternative to systemic thrombolysis or surgical embolectomy. Ultrasound-assisted catheter-directed thrombolysis is a contemporary catheter-based technique and is the focus of the present review. Ultrasound-assisted catheter-directed thrombolysis is more effective in reversing right ventricular dysfunction and dilatation in comparison with anticoagulation alone in patients at intermediate risk. However, a direct comparison of ultrasound-assisted thrombolysis with systemic thrombolysis or surgical thrombectomy is not available. Ultrasound-assisted thrombolysis with initial intrapulmonary thrombolytic bolus may also be effective in high-risk patients, but evidence from randomized trials is not available. This review summarizes current data on ultrasound-assisted thrombolysis for acute pulmonary embolism.

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BACKGROUND For patients with acute iliofemoral deep vein thrombosis, it remains unclear whether the addition of intravascular high-frequency, low-power ultrasound energy facilitates the resolution of thrombosis during catheter-directed thrombolysis. METHODS AND RESULTS In a controlled clinical trial, 48 patients (mean age 50±21 years, 52% women) with acute iliofemoral deep vein thrombosis were randomized to receive ultrasound-assisted catheter-directed thrombolysis (N=24) or conventional catheter-directed thrombolysis (N=24). Thrombolysis regimen (20 mg r-tPA over 15 hours) was identical in all patients. The primary efficacy end point was the percentage of thrombus load reduction from baseline to 15 hours according to the length-adjusted thrombus score, obtained from standardized venograms and evaluated by a core laboratory blinded to group assignment. The percentage of thrombus load reduction was 55%±27% in the ultrasound-assisted catheter-directed thrombolysis group and 54%±27% in the conventional catheter-directed thrombolysis group (P=0.91). Adjunctive angioplasty and stenting was performed in 19 (80%) patients and in 20 (83%) patients, respectively (P>0.99). Treatment-related complications occurred in 3 (12%) and 2 (8%) patients, respectively (P>0.99). At 3-month follow-up, primary venous patency was 100% in the ultrasound-assisted catheter-directed thrombolysis group and 96% in the conventional catheter-directed thrombolysis group (P=0.33), and there was no difference in the severity of the post-thrombotic syndrome (mean Villalta score: 3.0±3.9 [range 0-15] versus 1.9±1.9 [range 0-7]; P=0.21), respectively. CONCLUSIONS In this randomized controlled clinical trial of patients with acute iliofemoral deep vein thrombosis treated with a fixed-dose catheter thrombolysis regimen, the addition of intravascular ultrasound did not facilitate thrombus resolution. CLINICAL TRIAL REGISTRATION URL http://www.clinicaltrials.gov. Unique identifier: NCT01482273.

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Quercetin is a potential chemopreventive and chemotherapeutic agent for pancreatic and other cancers. This study examined the distribution of quercetin in plasma, lung, liver, pancreas, and pancreatic cancer xenografts in a murine in vivo model and the uptake of quercetin in pancreatic cancer MiaPaCa-2 cells in a cellular in vitro model. Mice were randomly allocated to control or 0.2 and 1% quercetin diet groups utilizing the AIN93G-based diet (n = 12 per group) for 6 weeks. In addition, 6 mice from each group were injected weekly with the chemotherapeutic drug gemcitabine (120 mg/kg mouse, ip). MiaPaCa cells were collected from culture medium after cells were exposed to 30 muM quercetin for 0.5, 1, 2, 4, 8, and 24 h. Levels of quercetin and 3-O'-methylquercetin in mouse tissues and MiaPaCa-2 cells were measured by high-pressure liquid chromatography following enzymatic hydrolysis and then extraction. The study showed that quercetin is accumulated in pancreatic cancer cells and is absorbed in the circulating system, tumors, and tissues of pancreas, liver, and lung in vivo. A higher proportion of total quercetin found in tumors and pancreas is aglycones. Gemcitabine cotreatment with quercetin reduced absorption of quercetin in the mouse circulatory system and liver. Results from the study provide important information on the interpretation of the chemotherapeutic efficacy of quercetin.

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Lorazepam (LOR) is a 3-hydroxy-1,4-benzodiazepine that is chiral and undergoes enantiomerization at room temperature. In humans, about 75% of the administered dose of LOR is excreted in the urine as its 30-glucuronide. CE-MS with negative ESI was used to confirm the presence of LOR-30-glucuronide in urines that stemmed from a healthy individual who ingested 1 or 2 mg LOR, whereas free LOR could be detected in extracts prepared from enzymatically hydrolyzed urines. As the 30-glucuronidation reaction occurs at the chiral center of the molecule, two diastereoisomers can theoretically be formed, molecules that can no longer interconvert. The stereoselective formation of LOR glucuronides in humans and in vitro was investigated. MEKC analysis of extracts of the nonhydrolyzed urines suggested the presence of the two different LOR glucuronides in the urine. The formation of the same two diastereoisomers was also observed in vitro employing incubations of LOR with human liver microsomes in the presence of uridine 5'-diphospho-glucuronic acid as coenzyme. The absence of other coenzymes excluded the formation of phase I or other phase II metabolites of LOR. Both results revealed a stereoselectivity, one diastereoisomer being formed in a higher amount than the other. After enzymatic hydrolysis using beta-glucuronidase, these peaks could not be detected any more. Instead, LOR was monitored. Analysis of the extracts prepared from enzymatically hydrolyzed urines by MEKC in the presence of 2-hydroxypropyl-beta-CD revealed the enantiomerization process of LOR (observation of two peaks of equal magnitude connected with a plateau zone). The data presented provide for the first time the evidence of the stereoselectivity of the LOR glucuronidation in humans.

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The identification of 15N-labeled 3-nitrotyrosine (NTyr) by gas chromatography/mass spectroscopy in protein hydrolyzates from activated RAW 264.7 macrophages incubated with 15N-L-arginine confirms that nitric oxide synthase (NOS) is involved in the nitration of protein-bound tyrosine (Tyr). An assay is presented for NTyr that employs HPLC with tandem electrochemical and UV detection. The assay involves enzymatic hydrolysis of protein, acetylation, solvent extraction, O-deacetylation, and dithionite reduction to produce an analyte containing N-acetyl-3-aminotyrosine, an electrochemically active derivative of NTyr. We estimate the level of protein-bound NTyr in normal rat plasma to be approximately 0-1 residues per 10(6) Tyr with a detection limit of 0.5 per 10(7) Tyr when > 100 nmol of Tyr is analyzed and when precautions are taken to limit nitration artifacts. Zymosan-treated RAW 264.7 cells were shown to have an approximately 6-fold higher level of protein-bound NTyr compared with control cells and cells treated with N(G)-monomethyl-L-arginine, an inhibitor of NOS. Intraperitoneal injection of F344 rats with zymosan led to a marked elevation in protein-bound NTyr to approximately 13 residues per 10(6) Tyr, an approximately 40-fold elevation compared with plasma protein of untreated rats; cotreatment with N(G)-monomethyl-L-arginine inhibited the formation of NTyr in plasma protein from blood and peritoneal exudate by 69% and 53%, respectively. This assay offers a highly sensitive and quantitative approach for investigating the role of reactive byproducts of nitric oxide in the many pathological conditions and disease states associated with NO(X) exposure such as inflammation and smoking.

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A method for the determination of menthol and menthol glucuronide (M-G) after enzymatic hydrolysis in plasma and urine of rats and humans was developed using headspace solid phase microextraction and gas chromatography-mass spectrometry in the selected ion monitoring mode (HS-SPME/GC-MS). The assay linearity for plasma ranged from 5 to 1000 ng/ml. The limit of quantification (LOQ) in plasma was 5 ng/ml. The intra- and inter-day precision for menthol and M-G were < or = 18.1% R.S.D. at the LOQ and < or = 4.0% at higher concentrations. Menthol and M-G were determined in rat and human plasma and urine after administration of menthol.

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A method using gas chromatography-mass spectrometry (GC-MS) and solid-phase extraction (SPE) was developed for the determination of ajulemic acid (AJA), a non-psychoactive synthetic cannabinoid with interesting therapeutic potential, in human plasma. When using two calibration graphs, the assay linearity ranged from 10 to 750 ng/ml, and 750 to 3000 ng/ml AJA. The intra- and inter-day precision (R.S.D., %), assessed across the linear ranges of the assay, was between 1.5 and 7.0, and 3.6 and 7.9, respectively. The limit of quantitation (LOQ) was 10 ng/ml. The amount of AJA glucuronide was determined by calculating the difference in the AJA concentration before ("free AJA") and after enzymatic hydrolysis ("total AJA"). The present method was used within a clinical study on 21 patients suffering from neuropathic pain with hyperalgesia and allodynia. For example, plasma levels of 599.4+/-37.2 ng/ml (mean+/-R.S.D., n=9) AJA were obtained for samples taken 2 h after the administration of an oral dose of 20 mg AJA. The mean AJA glucuronide concentration at 2h was 63.8+/-127.9 ng/ml.

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The DNA analogue tricyclo-DNA, built from conformationally rigid nucleoside analogues that were linked via tertiary phosphodiester functions, can efficiently be synthesized from the corresponding phosphoramidites by conventional solid-phase cyanoethyl phosphoramidite chemistry. 5'-End phosphorylated tricyclo-DNA sequences are chemically stable in aqueous, pH-neutral media at temperatures from 0 to 90 C. Tricyclo-DNA sequences resist enzymatic hydrolysis by the 3'-exonuclease snake venom phosphodiesterase. Homobasic adenine- and thymine-containing tricyclo-DNA octa- and nonamers are extraordinarily stable A-T base-pairing systems, not only in their own series but also with complementary DNA and RNA. Base mismatch formation is strongly destabilized. As in bicyclo-DNA, the tricyclo-DNA purine sequences preferentially accept a complementary strand on the Hoogsteen face of the base. A thermodynamic analysis reveals entropic benefits in the case of hetero-backbone duplex formation (tricyclo-DNA/DNA duplexes) and both an enthalpic and entropic benefit for duplex formation in the pure tricyclo-DNA series compared to natural DNA. Stability of tricyclo-DNA duplex formation depends more strongly on monovalent salt concentration compared to natural DNA. Homopyrimidine DNA sequences containing tricyclothymidine residues form triplexes with complementary double-stranded DNA. Triple-helix stability depends on the sequence composition and can be higher when compared to that of natural DNA. The use of one tricyclothymidine residue in the center of the self-complementary dodecamer duplex (d(CGCGAAT t CGCG), t = tricyclothymidine) strongly stabilizes its monomolecular hairpin loop structure relative to that of the corresponding pure DNA dodecamer ( T m = +20 C), indicating (tetra)loop-stabilizing properties of this rigid nucleoside analogue.

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This paper presents methods based on Information Filters for solving matching problems with emphasis on real-time, or effectively real-time applications. Both applications discussed in this work deal with ultrasound-based rigid registration in computer-assisted orthopedic surgery. In the first application, the usual workflow of rigid registration is reformulated such that registration algorithms would iterate while the surgeon is acquiring ultrasound images of the anatomy to be operated. Using this effectively real-time approach to registration, the surgeon would then receive feedback in order to better gauge the quality of the final registration outcome. The second application considered in this paper circumvents the need to attach physical markers to bones for anatomical referencing. Experiments using anatomical objects immersed in water are performed in order to evaluate and compare the different methods presented herein, using both 2D as well as real-time 3D ultrasound.