生物医学测量及控制技术新进展

介绍生物医学测量及控制技术领域中的一些研究进展。     

Automated preparation for identification and antimicrobial susceptibility testing: evaluation of a research use only prototype,the BD Kiestra IdentifA/SusceptA system

ObjectiveThe current BD Kiestra? total laboratory automation (TLA) system automates specimen inoculation, incubation, and digital visualization of cultures prior to initiation of manual or semi-automated identification (ID) and antimicrobial susceptibility testing (AST). The current study aimed to compare the performance, in a clinical setting, of a fully automated research-use-only prototype, BD Kiestra? IdentifA/SusceptA (automated system), to our current BD Kiestra? TLA which utilizes manual or semi-automated IDs and ASTs (current system).MethodsClinical samples yielding significant growth after processing by the BD Kiestra? TLA were tested in parallel for ID and AST by both systems. IDs and ASTs were determined by Bruker matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and BD Phoenix, respectively, with data stored and managed in the BD EpiCenter?. The automated system used a common inoculum preparation for both tests, whereas the current system used separate inocula. Results were compared to assess agreement between the systems.ResultsOn initial testing, 89% of IDs (466/523) and 92.4% of IDs (484/523) for the automated and current ID systems, respectively, yielded acceptable MALDI-TOF log scores of ≥1.7. On repeat testing, the respective acceptable scores were 97.1% (508/523) and 98.1% (513/523). For initial ASTs, the automated and current systems yielded 97.5% categorical agreement for 7325 drug–organism tests. After omitting discrepant MICs that differed by only one dilution and categorical discrepancies that were not reproducible, 0.2% unresolved discrepancies remained thus (99.8% categorical agreement).ConclusionsThe automated prototype is suitable for development into technology that will provide clinical microbiology laboratories with significant advantages such as improved efficiency, standardization, reproducibility, reduced technical error and greater safety.     

Multiple specificities of antibrain antibodies in multiple sclerosis and chronic myelopathy

The presence of complement-fixing antibodies against brain antigens was tested in paired serum and cerebrospinal fluid (CSF) samples from 60 multiple sclerosis (MS) patients, 15 patients with chronic myelopathy of undetermined cause (CM) and 60 control patients. Six MS sera, 34 MS CSF, 4 CM sera, 3 CM CSF, 4 control sera and 1 control CSF gave positive reactions either with a lipid extract or a saline extract of normal human brain. The proportion of anticomplementary CSF was significantly higher in the MS group than in the control group (15% vs 0%, P < 0.01). The reactivity of a large number of individual positive samples was further investigated. Seven antibody specificities were discerned in the MS samples. Most samples reacted with nonlipid antigens, the dominating being a heat-labile, nonlipid component associated with CNS myelin. Antibodies to cerebroside and sulfatide were detected in a few patients. A number of samples reacted with cholesterol in combination with a variety of lipids. Positive samples from the CM patients exhibited a similar heterogeneity. In the control group positive reactions were seen in one patient with systemic lupus erythematosus (SLE), two patients with rheumatoid arthritis (RA), and one with a spinal meningioma. The reaction patterns of these patients were different from those commonly seen in MS patients. The complement-fixing antibrain antibodies in MS CSF are usually of IgG class (Ryberg 1976). This applies also to the positive MS sera in this study. The distribution of the antibodies between serum and CSF indicated, in several cases, an intrathecal synthesis. All of a number of human brains, including one MS brain, contained all 6 antigens (haptens) reactive in saline extracts. Antibodies to tissues outside the CNS were rarely detected in MS patients. The varied humoral autoimmune response in MS might reflect a heterogeneity in the MS patients, the disease itself or its causative agent.     

银屑病患者外周血单个核细胞中CTLA4 mRNA及蛋白的表达

目的：了解细胞毒性T淋巴细胞相关抗原4（CTLA4、CD152）mRNA及蛋白在银屑病患者外周血单个核细胞（PBMC）中的表达情况。方法：利用金葡菌肠毒素B（SEB）刺激PBMC体外增殖，采用原位杂交和ABC免疫组化方法检测寻常型现患者PBMC中CTLA4的表达。结果：银屑病患者PBMC中CTLA4 mRNA及蛋白的表达明显弱于正常人，其中进行期更弱于静止期。结论 CTLA4在银屑病患者PBMC中的表达缺陷提示CTLA4可能在银屑病发病中起一定作用。     

引入全实验室自动化系统后的流程改造

全实验室自动化（TLA）代表着检验医学全程自动化的方向。对引入TLA技术后的医院整个检验过程的流程进行了详细描述,并讨论了流程实施中的一些关键问题。     

Performance of dual source versus 256-slice multi-slice CT in the evaluation of 16 coronary artery stents

Introduction

Invasive coronary angiography is the reference method for identification of in-stent restenosis (ISR) bearing the disadvantages of high costs and invasiveness. New approaches like dual-source CT (DSCT) and 256-multi-slice CT (256-MSCT) may potentially be the future methods of choice to reliably exclude ISR in patients with low or intermediate risk of restenosis.We sought to compare the performance of DSCT and 256-MSCT for the in vitro assessment of stent lumen diameter and basic scan parameters in stents of various diameters and designs.

Materials and Methods

In 16 coronary artery stents we evaluated relative in-stent lumen diameter, attenuation, noise, attenuation-/signal-to-noise ratio (ANR/SNR) and radiation dose (CTDI_vol) in an acknowledged coronary vessel in vitro phantom (iodine-filled plastic tubes) with DSCT (Siemens, SOMATOM Definition, collimation = 2 × 64 × 0.6 mm, pitch = 0.26, current = 400 mAs/rot, voltage = 120 kV, tube-rotation-time = 330 ms) and 256-MSCT (Philips Brilliance, iCT, tube collimation = 2 × 128 × 0.625 mm, pitch = 0.18, current = 800 mAs_eff, voltage = 120 kV, tube-rotation-time = 270 ms). Diameter analysis was conducted with the observer-independent full-width-at-half-maximum (FWHM) technique.

Results

DSCT and 256-MSCT revealed similar stent lumen diameters (50.7 ± 7.2% vs. 50.8 ± 7.4%, p = 0.98). Attenuation (−19 ± 25 HU vs. 54 ± 29 HU), ANR (−0.9 ± 1.2 vs. 2.9 ± 1.8) and SNR (12.1 ± 2.4 vs. 17.4 ± 1.9) were better in the DSCT (all p < 0.001) at the expense of significantly higher radiation doses (CTDI_vol = 87 vs. 51 mGy, p < 0.01). Noise was comparable (21 ± 2 HU vs. 20 ± 2 HU, p = n.s.). Only stents with a diameter >3 mm allowed sufficient stent lumen assessment in both scanners and showed a relative lumen diameter of 60–66%.

Conclusions

The measured stent lumen diameter and image noise were similar in both scanners. Yet the DSCT offered a more truthful stent lumen visualization at the cost of higher radiation dose.Applying the FWHM approach only stents with a diameter >3 mm offered sufficient stent lumen assessment.     

Tumescent local anesthesia in inguinal herniorrhaphy with a PROLENE Hernia System: original technique and results

Background

Local anesthesia (LA) for inguinal herniorrhaphy has many advantages, but its practical use is rare. We presented a new method, tumescent local anesthesia (TLA), for inguinal herniorrhaphy with a PROLENE hernia system (PHS).

Methods

Sixty-six patients underwent inguinal herniorrhaphy with PHS under TLA of .05% lidocaine and .0125% bupivacaine diluted in normal saline with epinephrine (1:1,000,000) and 10 mEq/L of sodium bicarbonate.

Results

No patients required conversion to general anesthesia. The mean dose of lidocaine was 188.1 ± 40.5 mg, and the mean duration of surgery was 73.4 ± 23.8 minutes. Intraoperative sedation was required in 1.5% of patients, and painkillers in the early postoperative period were required in 13.6%. No recurrence was observed up to 2 years after surgery.

Conclusions

Our results suggest that the TLA technique is safe and applicable in inguinal herniorrhaphy and may have some beneficial effects regarding intra- and postoperative analgesia.     

全实验室自动化系统引入后医院检验过程的流程改造

全实验室自动化(TLA)代表着检验医学全程自动化的方向。本文对引入TLA技术后的医院整个检验过程的流程进行了详细描述,并讨论了流程实施中的一些关键问题。