Feasibility of contrast-enhanced sonography during resection of cerebral tumours: initial results of a prospective study

The aim of this study was to adapt the ultrasonographical techniques developed for brain perfusion imaging to an intraoperative setting for topographic diagnosis of cerebral tumours. During surgery, the patients underwent contrast-enhanced ultrasonography (phase inversion harmonic imaging, bolus kinetic, fitted model function). Endocavity curved array (6.5EC10, 6.5 MHz) was used intraoperatively. The ultrasound contrast agent SonoVue (Bracco) was administered IV as a bolus injection. Off-line, time-intensity curves as well as perfusion maps were calculated and parameters such as peak intensity were locally extracted to characterise perfusion. Seven patients with brain tumours of different histologic types were subjected to contrast-enhanced ultrasonography during surgery. Tissue differentiation with contrast agent was superior to conventional B-mode ultrasound imaging. Intraoperative contrast-enhanced ultrasonography enabled visualisation of cerebral tumours in high spatial resolution.     

四川地区供血浆者病毒指标筛查结果与确认试验的对比分析

目的通过比较ELISA法筛查供血浆者血浆HBs Ag、抗-HCV、抗-HIV结果和确认试验结果,分析不同检测值标本的确认阳性符合率。方法采用进口ELISA试剂,HBs Ag采用中和试验法进行确认、抗-HCV和抗-HIV采用重组免疫印迹法对ELISA筛查阳性标本208份进行确认,确认试验结果为不确定的标本采用NAT法检测,将2者结果进行对比分析。结果国产和进口ELISA试剂检测HBs Ag、抗-HCV、抗-HIV的确认阳性符合率分别为92.86%、94.74%和85.71%,3者比较差异无统计学意义(P0.05)。结论对国产ELISA检测试剂用于供血浆者HBs Ag、抗-HCV、抗-HIV 3项检测的效果进行了科学评价,为假阳性供血浆者管理及ELISA检测试剂的选择提供了试验依据。     

Feasibility of pulse oximetry in the initial prehospital management of victims of drowning: a preliminary study

Aim

Immediate delivery of oxygen is the most important treatment for victims of drowning at the rescue site. Monitoring oxygen saturation with pulse oximetry is potentially useful, but its use may be limited by poor peripheral perfusion due to hypothermia. This preliminary study explores the feasibility of pulse oximetry in simulated minor drowning scenarios.

Materials and methods

Six different pulse oximeters were tested on ten healthy volunteers after brief submersion, after ten minutes of swimming in a swimming pool (warm water, temperature 21 °C), and in the sea (cold water, temperature 16 °C). A measured oxygen saturation reading ≤94% was assumed to be incorrect.

Results

There was considerable variability between each pulse oximeter. In warm water, 5.8% of measurements were outside the predicted range (8.3% after submersion, 3.3% after swimming), compared to 34% in cold water (20% after submersion, 48% after swimming). The spurious measurements came from two pulse oximeters in warm water, but from all six in cold water. The best and worst performing pulse oximeters showed 5% and 33% measurements respectively outside the predicted range.

Conclusion

The performance of pulse oximeters varies considerably in healthy volunteers submersed or immersed in warm or cold water. Further studies are needed to understand these differences.     

International comparative field study evaluating the assay performance of AFSTYLA in plasma samples at clinical hemostasis laboratories

Essentials

• AFSTYLA exhibits ≈50% underestimation in activity when the one‐stage (OS) assay is utilized.
• A field study compared the performance of AFSTYLA with Advate in factor VIII activity assays.
• AFSTYLA activity can be monitored with both the chromogenic substrate and the OS assay.
• The consistent OS underestimation allows for a conversion factor to be applied to OS results.

Summary

Introduction

AFSTYLA (antihemophilic factor [recombinant] single chain) is a novel B‐domain truncated recombinant factor VIII (rFVIII). For AFSTYLA, an approximate 50% discrepancy was observed between results of the one‐stage (OS) and chromogenic substrate (ChS) FVIII activity assays. An investigation was undertaken to test whether there is a linear relationship between ChS and OS assay results that would allow reliable clinical interpretation of results independent of the assay method used.

Aims

To provide confidence in future clinical monitoring, this field study investigated the performance of AFSTYLA and a full‐length rFVIII (Advate^®) in FVIII activity assays routinely performed in clinical laboratories.

Methods

The comparison of AFSTYLA and Advate was performed in an international, multicenter and blinded field study of simulated post‐infusion samples. The study documented the extent of variability between methods and laboratories and characterized the relationship between the ChS and OS assays.

Results

Results from 23 laboratories demonstrate that intra and interlaboratory variability in OS assays were similar for both products. When comparing within the OS assay format, there was a similar and reagent‐correlated variability in response to different activators for both AFSTYLA and Advate. The OS underestimation was highly predictable and consistent across the complete range of FVIII plasma concentrations.

Conclusion

Post‐infusion plasma AFSTYLA levels can be monitored in patients by the OS and ChS assays. The consistent and predictable difference between the two assay formats provides clinicians with adequate guidance on how to interpret the results of the OS assay using a single conversion factor.     

Point-of-care time-resolved immunofluorometric assay for human pregnancy-associated plasma protein A: use in first-trimester screening for Down syndrome

BACKGROUND: Screening for Down syndrome in the first trimester by a combination of fetal nuchal translucency thickness and maternal serum pregnancy-associated plasma protein A (PAPP-A) and free beta-human chorionic gonadotropin has been shown to be effective and efficient. We aimed to develop a fast point-of-care assay that could be placed in one-stop clinics for the measurement of PAPP-A. METHODS: We developed a two-site, one-step assay that uses two monoclonal antibodies (mAbs) to PAPP-A, based on a dry-reagent, all-in-one immunoassay concept with a stable fluorescent lanthanide chelate and time-resolved fluorometry. One antibody (mAb 10E1) was biotinylated, and the other (mAb 234-5) was europium-labeled, both via the epsilon-amino groups of surface lysine residues. The assay was performed on an AIO immunoanalyzer at 36 degrees C in single, streptavidin-coated microtitration wells that contained the dry reagents. PAPP-A, either in free or complexed form, was detected by the antibodies used. RESULTS: The assay procedure required 20 min and used 10 microL of sample. The calibration curve was linear from 5 to 10 000 mIU/L. The detection limit was 0.5 mIU/L. Intra- and interassay imprecision (CV) was < or = 4.3% and 8.3%, respectively, for whole blood, plasma, or serum samples. Recovery was 93-96% for serum, 95-108% for heparin-derived whole blood, and 98-103% for heparin-derived plasma. Parallelism was observed in all three matrices. Results correlated [slope = 0.85 (confidence interval, 0.82-0.87); intercept = -33 (confidence interval, -58 to -9); S(y:x) = 85 mIU/L; r = 0.991; n = 100] with those obtained by a Delfia assay. Heparin did not affect the assay, but EDTA markedly reduced PAPP-A values. PAPP-A was stable at 4 degrees C for at least 18 days in serum and for 8 days in heparin-derived whole blood or plasma. CONCLUSIONS: The present assay appears suited for use in one-stop clinics for screening for Down syndrome in the first trimester, with results available within 1 h.     

Human platelets as a substrate source for the in vitro amplification of the abnormal prion protein (PrP) associated with variant Creutzfeldt-Jakob disease

BACKGROUND: Four recent cases of transfusion-related transmission of variant Creutzfeldt-Jakob disease (vCJD) highlight the need to develop a highly sensitive and specific screening test to detect infectivity in the blood of asymptomatic infected individuals. Protein misfolding cyclic amplification (PMCA), a method for the amplification of minute amounts of disease-associated abnormal prion protein (PrP^Sc) to readily detectable levels, could be incorporated into such a test provided that a suitable substrate source for routine use in human PMCA reactions can be found.
STUDY DESIGN AND METHODS: With the use of seed sources from individuals with variant and sporadic CJD, the use of human platelets (PLTs) as a PMCA substrate source was evaluated. The effects of seed/substrate prion protein gene ( PRNP ) codon 129 genotype compatibility on amplification efficiency and freeze-thaw on a substrate's ability to support amplification and the degree of amplification achieved by serial PMCA (sPMCA) were investigated.
RESULTS: Seed/substrate PRNP codon 129 compatibility was found to have a major influence on PrP^Sc amplification efficiency. Individual substrates, of the same PRNP codon 129 genotype, could be pooled and stored frozen for use in subsequent PMCA reactions. A consistent 10-fold increase in PrP^Sc detection sensitivity was achieved after each round of sPMCA, resulting in a 10,000-fold increase in detection sensitivity after four rounds, with no evidence of de novo PrP^Sc production detected in the unseeded PLT substrate.
CONCLUSIONS: Providing issues of seed/substrate PRNP codon 129 compatibility are taken into consideration human PLTs are a suitable, readily available, renewable substrate source for use in human PMCA applications.     

一体化急诊创伤外科运作模式初期实践的可行性分析

目的：评价以普外科为基础的初期一体化急诊创伤外科运作模式在诊疗相关患者方面的效用和所收治患者的主要特点,并与以往分科共诊模式进行比较。方法：采集急诊创伤外科成立之前和之后各2年半收治入院的155名急诊外科创伤患者,对其伤情特点、收治效率、转归情况等方面进行比较。结果：所有收入院患者中以男性患者为主,平均年龄47．92岁,交通事故伤为致创首因,腹部、颅面部、前胸部为易伤部位。就诊和入院的高峰时间分布为8点至24点及12点至20点。创伤组手术患者入院前滞留时间（t=2．115,P〈O．05）、入院至手术时间（t=2．381,P〈O．05）、投诉纠纷事件（x^2=7．232,P〈O．01）均短于或少于传统组。结论：以普外科为基础的初期一体化急诊创伤外科运作模式能够缩短患者入院或至急诊手术时间,提高伤员救治的及时性和连贯性,有利于减轻目前三级医院普遍较为严重的急诊患者的滞留问题及降低医疗投诉纠纷等隐患。可能对改善患者预后及缩短住院时间有所帮助,具有可行性。     

Direct identification of chlamydiae from clinical samples using a DNA microarray assay: a validation study

While DNA microarrays have become a widely accepted tool for mRNA expression monitoring, their use in rapid diagnosis of bacterial and viral pathogens is only emerging. So far, insufficient sensitivity and high costs have been the major limiting factors preventing more widespread use of microarray platforms in direct testing of clinical samples. In the present study, a total of 339 samples, among them 293 clinical specimens from animals and humans, were examined by the ArrayTube (AT) DNA microarray assay to detect chlamydial DNA and identify the species of Chlamydia and Chlamydophila involved. Samples included nasal and conjunctival swabs, formalin-fixed, paraffin-embedded and fresh organ tissue, milk, feces and cell culture. Notably, the AT test was shown to detect mixed infections in clinical samples. The calculated median sensitivity of 0.81 over the entire panel of clinical samples was comparable to conventional 16S PCR, but slightly lower than real-time PCR and other PCR assays. However, when a panel of long-time stored swab samples was excluded from the calculation, the sensitivity was clearly higher (0.87) and equivalent to that of real-time PCR. Altogether, the data demonstrate the suitability of this DNA microarray assay for routine diagnosis.     

Pregnancy-associated plasma protein A values in patients with stable cardiovascular disease: use of a new monoclonal antibody-based assay

BackgroundPAPP-A is promising in improving risk stratification and invasive treatment decisions in stable cardiovascular patients. We evaluated the prognostic value of pregnancy-associated plasma protein A (PAPP-A) measured by a novel assay in stable cardiovascular patientsMethodsWe investigated 228 stable cardiovascular outpatients. Blood was drawn for PAPP-A measurement after echocardiography and ergometry prior to heart catheterization. Angiographically we determined severity as well as qualitative characteristics suspect for vulnerability of coronary lesions. After 1108 ± 297 days, follow-up information was obtained by questionnaire mailings and interviews by phone.Results104 patients had coronary stenosis ≥ 70%, 75 had B-type lesions ≥ 50%, 46 showed complex lesions, and 68 were suspected to have vulnerable lesions. Median PAPP-A was 1.76 (interquartile range 1.21, 2.63) μIU/ml in the entire cohort. PAPP-A concentrations did not differ in dependence on coronary artery findings. A cutpoint of 2.7 μIU/ml was derived from receiver–operator characteristics for outcome measures. For this cutoff, Cox proportional hazard models with 19 further clinical variables showed that PAPP-A was predictive for all-cause death (HR 4.73, 95% CI 1.46–15.31, p = 0.01), all-cause death or nonfatal infarction (HR 4.01, 95% CI 1.58–10.13, p = 0.003) and all-cause death, nonfatal myocardial infarction or hospitalization (HR 1.96, 95% CI 1.03–3.70, p = 0.04). The predictive value of PAPP-A did not change substantially after correction for values of cardiac troponin, using a highly sensitive cardiac troponin I research assay.ConclusionsPAPP-A, measured by a new, monoclonal antibody-based assay is a promising prognostic marker in patients with stable cardiovascular disease and an indication for heart catheterization.     

The cholesterol risk factor--initial results of a screening study in industries

After the distribution of suitably informative leaflets all the employees of 2 companies were invited to participate in a screening programme with the aim of detecting elevated cholesterol levels. 238 out of 510 employees participated in the screening. Related to the age-adjusted Austrian recommendations for the upper limit of normal values, cholesterol was elevated in 73 people (30.7%). The percentage of smokers was slightly below the Austrian rate with 26% in company M and 30% in company H. All the participants were informed of their laboratory results within one week. Participants with a moderately or extremely increased risk were invited to a personal talk. Furthermore, a number of other previously undetected abnormalities were detected in 41 cases (17.2%), leading to subsequent clinical diagnosis and treatment. In addition, 3 plasma factor defects were discovered. These investigations served as a foundation for a more intensive planned programme. A continuation of this screening procedure is planned involving about 10,000 people per year.     

Extracorporeal plasma treatment for the removal of endotoxin in patients with sepsis: clinical results of a pilot study

Despite the advances in therapeutic approaches in the management of inflammatory conditions, the incidence of sepsis is on increase in the intensive care units (ICU). In a pilot study, we investigated whether the use of an apheresis system based on DEAE-cellulose is capable of reducing the plasma concentration of endotoxin in patients with severe sepsis. We enrolled 15 intensive care patients with severe sepsis and plasma endotoxin concentrations >0.3 EU/mL. In addition to standard ICU therapy, a total of 83 apheresis treatments were performed. About 1.7 volumes of plasma (6000 mL) were treated at each apheresis session. A significant reduction in plasma endotoxin levels from a median of 0.61 to 0.39 EU/mL (-35%) could be achieved (P < 0.001). Long-term comparison of the initial and post-treatment levels after a series of five to six individual apheresis treatments also showed a statistically significant decline in circulating endotoxin, interleukin (IL)-6, C-reactive protein (CRP), fibrinogen, and an increase in cholesterol levels. Except for a transient and reversible increase of prothrombin time, no adverse events were observed in patients undergoing this new adsorption apheresis treatment. Our data show that reduction of endotoxin by extracorporeal DEAE-cellulose-based plasma treatment may prove a promising therapeutic tool for patients suffering from bacterial sepsis and proven endotoxemia.     

Improving adherence to screening follow-up among women with abnormal Pap smears: results from a large clinic-based trial of three intervention strategies.

In a large randomized trial involving over 2,000 women with abnormal cervical cytology (pap smear), three clinic-based interventions were tested as strategies to increase return rates for screening follow-up: 1) a personalized follow-up letter and pamphlet; 2) a slide-tape program on pap smears; and 3) transportation incentives (bus passes/parking permits). The three interventions were evaluated using a 2 x 2 x 2 factorial design. Results of this study confirm a high rate of loss to screening follow-up (i.e., no return visits) among women with abnormal pap smears (29% overall), with substantial variability among the 12 participating clinics (13% to 42/%). For the sample as a whole, both transportation incentives and the combined intervention condition of personalized follow-up and slide-tape program had a significant positive impact on screening follow-up. However, transportation incentives emerged as the dominant intervention condition among patient subgroups that can be characterized as more disadvantaged socioeconomically and at higher risk of developing cervical cancer, including patients receiving care from the county health department (odds ratio (OR) = 1.51; P less than .05); patients without health insurance (OR = 1.77; P less than .01); and patients with more severe pap smear results (OR = 1.71; P less than .05). In contrast, among patient subgroups that can be characterized as relatively more advantaged and at lower risk of developing cervical cancer, only the combined intervention condition of personalized follow-up and slide-tape program was associated with a higher patient return rate. Subgroups reflecting this pattern included patients seen in noncounty clinics (OR = 4.54; P less than .05) and patients with less severe pap smear results (OR = 5.16; P less than .01). The implications of these findings are discussed in terms of designing clinic-based interventions to improve screening follow-up.     

Increased detection of hepatitis C virus infection in commercial plasma donors by a third-generation screening assay

BACKGROUND: Routine screening of blood donations with second-generation hepatitis hepatitis C virus (HCV) assays has substantially reduced the occurrence of posttransfusion hepatitis. However, following the development of third-generation assays, several studies indicated that these assays may identify HCV-infected individuals who are not identified by second-generation assays. STUDY DESIGN AND METHODS: The sensitivity of a third-generation HCV enzyme-linked immunosorbent assay (ELISA-3) was compared with a second-generation ELISA (ELISA-2) in a side-by-side study of 9936 commercial blood donors. ELISA-reactive specimens were subjected to supplemental analysis by third-generation recombinant immunoblot assay and polymerase chain reaction. RESULTS: ELISA-3 demonstrated greater sensitivity than ELISA-2, detecting 1 additional recombinant immunoblot assay-positive specimen per 2000 tested. ELISA-3 also detected 1 additional HCV-infectious polymerase chain reaction-positive unit among approximately 10,000 units screened. CONCLUSION: The incremental sensitivity achieved with ELISA-3 can be expected to eliminate approximately 20 infectious donations per week among those made by commercial donors in the United States. In accordance with previous studies, most of the improved sensitivity of ELISA-3 derives from its increased detection of anti-c33c (NS3), rather than from the inclusion of HCV antigen NS5.     

Effectiveness of trans-retinoic acid in the treatment of acute promyelocytic leukemia: initial results of a multicenter study]

AIM: Evaluation of trans-retinoic acid (ATRA) in combination with cytostatic drugs in treatment of acute promyelocytic leukemia (APL). MATERIALS AND METHODS: In a multicenter study APL was treated according to protocols APL 01.97 and APL 06.87 in 28 patients (14 males and 14 females, median age 36 years). RESULTS: Administration of ATRA in combination with standard program 7 + 3 (cytosine-arabinoside 100 mg/m2 twice a day v.v. day 1-7, daunorubicin 60 mg/m2 v.v. day 1-3) induced a complete remission in 25 patients (90%). Early lethality was 10% (3 patients died). Resistant APL was not registered. Retinoid syndrome was diagnosed in 15 patients, one patient died. 2-year overall and recurrence-free survival made up 72 and 82%, respectively. CONCLUSION: ATRA combination with cytosine-arabinoside and daunorubicin is a novel treatment of acute promyelocytic leukemia providing a high rate of complete remission and long-term survival.     

Fast functional assay of protein C in whole plasma using a snake venom activator: evaluation in patients with congenital and acquired protein C deficiencies

Both anticoagulant and amidolytic activities of protein C (PC) were measured using a snake venom activator in 4 patients with hereditary PC deficiency, 37 with disseminated intravascular coagulation (DIC), and 30 under stabilized warfarin therapy. The results were compared with those obtained by an immunological assay (ELISA). PC levels measured by different functional and immunological assays were very close in patients with hereditary PC deficiency and DIC. In patients under stable oral anticoagulant therapy, there was no detectable difference between amidolytic activity and antigen levels of PC in each patient plasma, whereas a decrease in anticoagulant activity was much more pronounced. These results indicate that the present activity assays measure PC specifically, and that the snake venom activator is capable of activating both carboxylated and hypocarboxylated forms of PC, but only anticoagulant assay can evaluate the physiological PC function in vitamin K-deficient states.