878 resultados para salicylate sensitive electrode
Resumo:
BACKGROUND: Ankle-brachial pressure index (ABI) is a simple, inexpensive, and useful tool in the detection of peripheral arterial occlusive disease (PAD). The current guidelines published by the American Heart Association define ABI as the quotient of the higher of the systolic blood pressures (SBPs) of the two ankle arteries of that limb (either the anterior tibial artery or the posterior tibial artery) and the higher of the two brachial SBPs of the upper limbs. We hypothesized that considering the lower of the two ankle arterial SBPs of a side as the numerator and the higher of the brachial SBPs as the denominator would increase its diagnostic yield. METHODS: The former method of eliciting ABI was termed as high ankle pressure (HAP) and the latter low ankle pressure (LAP). ABI was assessed in 216 subjects and calculated according to the HAP and the LAP method. ABI findings were confirmed by arterial duplex ultrasonography. A significant arterial stenosis was assumed if ABI was <0.9. RESULTS: LAP had a sensitivity of 0.89 and a specificity of 0.93. The HAP method had a sensitivity of 0.68 and a specificity of 0.99. McNemar's test to compare the results of both methods demonstrated a two-tailed P < .0001, indicating a highly significant difference between both measurement methods. CONCLUSIONS: LAP is the superior method of calculating ABI to identify PAD. This result is of great interest for epidemiologic studies applying ABI measurements to detect PAD and assessing patients' cardiovascular risk.
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Chronic pancreatitis is a common inflammatory disease of the pancreas. Mutations in the genes encoding cationic trypsinogen (PRSS1) and the pancreatic secretory trypsin inhibitor (SPINK1) are associated with chronic pancreatitis. Because increased proteolytic activity owing to mutated PRSS1 enhances the risk for chronic pancreatitis, mutations in the gene encoding anionic trypsinogen (PRSS2) may also predispose to disease. Here we analyzed PRSS2 in individuals with chronic pancreatitis and controls and found, to our surprise, that a variant of codon 191 (G191R) is overrepresented in control subjects: G191R was present in 220/6,459 (3.4%) controls but in only 32/2,466 (1.3%) affected individuals (odds ratio 0.37; P = 1.1 x 10(-8)). Upon activation by enterokinase or trypsin, purified recombinant G191R protein showed a complete loss of trypsin activity owing to the introduction of a new tryptic cleavage site that renders the enzyme hypersensitive to autocatalytic proteolysis. In conclusion, the G191R variant of PRSS2 mitigates intrapancreatic trypsin activity and thereby protects against chronic pancreatitis.
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Diagnosis of udder infections with Staphylococcus aureus by bacteriological milk testing of quarter milk samples is often not satisfactory. To get reliable results, repeated sampling is necessary, which is normally too expensive. Therefore, we developed a test that allows the highly specific detection of Staph. aureus in bovine milk samples at very low concentrations. It is based on a fast procedure to prepare bacteria from milk, followed by DNA extraction and quantitative PCR. The whole analysis is done within 5 h. For clinical milk samples, the analytical sensitivity of the assay was 50.7 times and 507 times higher than conventional bacteriology with 100 and 10 microL, respectively. The diagnostic specificity was 100%. The test is further characterized by a low intra- and interassay variability as well as by a good recovery of Staph. aureus from raw milk. Furthermore, a high correlation (R = 0.925) between the agar plate counts and the quantitative PCR methodology over the whole range of measurement was found. In addition, our test revealed considerably more positive results than bacteriology. Due to its favorable properties, the assay might become an important diagnostic tool in the context of bovine mastitis caused by Staph. aureus.
Resumo:
AIMS: We investigated whether myeloid-related protein 8/14 complex (MRP8/14) expressed by infiltrating monocytes and granulocytes may represent a mediator and early biomarker of acute coronary syndromes (ACS). METHODS AND RESULTS: Immunohistochemistry of coronary thrombi was done in 41 ACS patients. Subsequently, levels of MRP8/14 were assessed systemically in 75 patients with ACS and culprit lesions, with stable coronary artery disease (CAD), or with normal coronary arteries. In a subset of patients, MRP8/14 was measured systemically and at the site of coronary occlusion. Macrophages and granulocytes, but not platelets stained positive for MRP8/14 in 76% of 41 thrombi patients. In ACS, local MRP8/14 levels [22.0 (16.2-41.5) mg/L] were increased when compared with systemic levels [13.4 (8.1-14.7) mg/L, P = 0.03]. Systemic levels of MRP8/14 were markedly elevated [15.1 (12.1-21.8) mg/L, P = 0.001] in ACS when compared with stable CAD [4.6 (3.5-7.1) mg/L] or normals [4.8 (4.0-6.3) mg/L]. Using a cut-off level of 8 mg/L, MRP8/14 but not myoglobin or troponin, identified ACS presenting within 3 h from symptom onset. CONCLUSION: In ACS, MRP8/14 is markedly expressed at the site of coronary occlusion by invading phagocytes. The occurrence of elevated MRP8/14 in the systemic circulation prior to markers of myocardial necrosis makes it a prime candidate for the detection of unstable plaques and management of ACS.
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Oxygen-sensitive 3He-MRI was studied for the detection of differences in intrapulmonary oxygen partial pressure (pO2) between patients with normal lung transplants and those with bronchiolitis obliterans syndrome (BOS). Using software developed in-house, oxygen-sensitive 3He-MRI datasets from patients with normal lung grafts (n = 8) and with BOS (n = 6) were evaluated quantitatively. Datasets were acqiured on a 1.5-T system using a spoiled gradient echo pulse sequence. Underlying diseases were pulmonary emphysema (n = 10 datasets) and fibrosis (n = 4). BOS status was verified by pulmonary function tests. Additionally, 3He-MRI was assessed blindedly for ventilation defects. Median intrapulmonary pO2 in patients with normal lung grafts was 146 mbar compared with 108 mbar in patients with BOS. Homogeneity of pO2 distribution was greater in normal grafts (standard deviation pO2 34 versus 43 mbar). Median oxygen decrease rate during breath hold was higher in unaffected patients (-1.75 mbar/s versus -0.38 mbar/s). Normal grafts showed fewer ventilation defects (5% versus 28%, medians). Oxygen-sensitive 3He-MRI appears capable of demonstrating differences of intrapulmonary pO2 between normal lung grafts and grafts affected by BOS. Oxygen-sensitive 3He-MRI may add helpful regional information to other diagnostic techniques for the assessment and follow-up of lung transplant recipients.
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The penetration of ertapenem, a new carbapenem with a long half-life, reached 7.1 and 2.4% into inflamed and noninflamed meninges, respectively. Ertapenem had excellent antibacterial activity in the treatment of experimental meningitis due to penicillin-sensitive and -resistant pneumococci, leading to a decrease of 0.69 +/- 0.17 and 0.59 +/- 0.22 log(10) CFU/ml x h, respectively, in the viable cell counts in the cerebrospinal fluid. The efficacy of ertapenem was comparable to that of standard regimens (ceftriaxone monotherapy against the penicillin-sensitive strain and ceftriaxone combined with vancomycin against the penicillin-resistant strain). In vitro, ertapenem in concentrations above the MIC was highly bactericidal against both strains. Even against a penicillin- and quinolone-resistant mutant, ertapenem had similar bactericidal activity in vitro.
Resumo:
BMS 284756 penetrated well into inflamed meninges (44% +/- 11%) and produced good bactericidal activity (-0.82 +/- 0.22 Delta log(10) CFU/ml. h) in the treatment of experimental meningitis in rabbits due to a penicillin-sensitive strain. BMS 284756 monotherapy had a greater potency than the standard regimen of ceftriaxone and vancomycin (-0.49 +/- 0.08 Delta log(10) CFU/ml. h) against a penicillin-resistant strain (MIC, 4 mg/liter). Even against a penicillin- and quinolone-resistant strain, BMS 284756 showed good bactericidal activity (-0.52 +/- 0.12 Delta log(10) CFU/ml. h). The antibacterial activity of BMS 284756 was confirmed by time-killing assays over 8 h in vitro.
Resumo:
Linezolid, a new oxazolidinone antibiotic, showed good penetration (38+/-4%) into the meninges of rabbits with levels in the CSF ranging from 9.5 to 1.8 mg/L after two i.v. injections (20 mg/kg). Linezolid was clearly less effective than ceftriaxone against a penicillin-sensitive pneumococcal strain. Against a penicillin-resistant strain, linezolid had slightly inferior killing rates compared with the standard regimen (ceftriaxone combined with vancomycin). In vitro, linezolid was marginally bactericidal at concentrations above the MIC (5 x and 10 x MIC).
Resumo:
The new fluoroquinolone trovafloxacin was tested against a ciprofloxacin-sensitive, methicillin-resistant Staphylococcus aureus strain in the rabbit model of endocarditis. Trovafloxacin was more effective than vancomycin (CFU/g of vegetation, 2.65 +/- 1.87 versus 4.54 +/- 2.80 [mean +/- standard deviation]; P < 0.05) or ampicillin-sulbactam plus rifampin (4.9 +/- 1.1 CFU/g). The addition of ampicillin-sulbactam to trovafloxacin tended to reduce titers further.
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PURPOSE: To determine whether the treatment of hypersensitive teeth with gaseous ozone (Healozone, KaVo 1600 ppm) for 60 seconds reduces pain immediately after treatment and in the longer term. METHODS: In three private practices in Switzerland, 31 subjects suffering from hypersensitive teeth were treated with gaseous ozone over a period of 54 weeks (one test and one control tooth in each subject). A cross-over design was chosen. The pain level was measured with a Visual Analogue Scale before and after the treatment. RESULTS: The subjects' pain level was reduced by 55% +/- 5.5% immediately after the ozone treatment. Over time, the pain level decreased significantly in all groups: The pain level in the test teeth was significantly reduced in Weeks 0-22 (treatment group, P < 0.001) compared to the pain level before treatment. The pain level in the control group was also reduced significantly over time in Weeks 0-22 (no-treatment, P = 0.025) and in Weeks 22-54 (treatment group, P = 0.0065). Comparing test and control teeth over time, there was no statistically significant difference in pain reduction (P = 0.58).
Resumo:
This thesis evaluates a novel asymmetric capacitor incorporating a carbon foam supported nickel hydroxide positive electrode and a carbon black negative electrode. A series of symmetric capacitors were prepared to characterize the carbon black (CB) negative electrode. The influence of the binder, PTFE, content on the cell properties was evaluated. X-ray diffraction characterization of the nickel electrode during cycling is also presented. The 3 wt% and 5 wt% PTFE/CB symmetric cells were examined using cyclic voltammetry (CV) and constant current charge/discharge measurements. As compared with symmetric cells containing more PTFE, the 3 wt% cell has the highest average specific capacitance, energy density and power density over 300 cycles, 121.8 F/g, 6.44 Wh/kg, and 604.1 W/kg, respectively. Over the 3 to 10 wt% PTFE/CB range, the 3 wt% sample exhibited the lowest effective resistance and the highest BET surface area. Three asymmetric cells (3 wt% PTFE/CB negative electrode and a nickel positive) were fabricated; cycle life was examined at 3 current densities. The highest average energy and power densities over 1000 cycles were 20 Wh/kg (21 mA/cm2) and 715 W/kg (31 mA/cm2), respectively. The longest cycle life was 11,505 cycles (at 8 mA/cm2), with an average efficiency of 79% and an average energy density of 14 Wh/kg. The XRD results demonstrate that the cathodically deposited nickel electrode is a typical α-Ni(OH)2 with the R3m structure (ABBCCA stacking); the charged electrodes are 3γ-NiOOH with the same stacking as the α-type; the discharged electrodes (including as-formed electrode) are aged to β’-Ni(OH)2 (a disordered β) with the P3m structure (ABAB stacking). A 3γ remnant was observed.