Microtia: ear reconstruction using tissue expander and autogenous costal cartilage

Ear reconstruction is one of the most challenging surgeries faced by the reconstructive surgeon. Currently, the use of autogenous costal cartilage is still best practice for microtia reconstruction. However, the relative deficiency of thin skin for coverage of the cartilage framework remains a limiting factor. Since 1994, we have used tissue expander in the mastoid area and innovated a technique to fabricate cartilage framework. All these innovations may solve the deficiency of the skin and improve cartilaginous framework definition. In conclusion, tissue expander offers a non-hairbearing, thin, well-vascularised skin to envelope an erect, contour-accentuated framework. Most patients with microtia are satisfied with their ear reconstruction.

CNTO 530: molecular pharmacology in human UT-7EPO cells and pharmacokinetics and pharmacodynamics in mice

CNTO 530 is a 58 kD antibody Fc domain fusion protein, created using Centocor's MIMETIBODY platform, that contains two EMP1 sequences as a pharmacophore. CNTO 530 has no sequence homology with EPO but acts as a novel erythropoietin receptor agonist. In UT-7(EPO) cells, CNTO 530 caused protein phosporylation of the erythropoietin receptor associated signaling pathway (Jak2, STAT5, AKT and ERK1/2). CNTO 530 also rescued these cells from apoptosis and mediated proliferation. In mice, pharmacokinetic analysis showed that CNTO 530 was slowly cleared from circulation with a t(1/2) approximately 40 h. Pharmacodynamic analysis in mice showed that a single sc dose of CNTO 530 caused a long-lived stimulation of erythropoiesis that translated into increases in red blood cell counts and hemoglobin values that were maintained for at least 28 d. In conclusion, CNTO 530 is a long-lived EPO-R agonist that stimulates erythropoiesis in a manner similar to epoetin-alpha. These data suggest that CNTO 530 may be an effective treatment of anemia in humans.

Hosing instability in the blow-out regime for plasma-wakefield acceleration

The electron hosing instability in the blow-out regime of plasma-wakefield acceleration is investigated using a linear perturbation theory about the electron blow-out trajectory in Lu et al. [in Phys. Rev. Lett. 96, 165002 (2006)10.1103/PhysRevLett.96.165002]. The growth of the instability is found to be affected by the beam parameters unlike in the standard theory Whittum et al. [Phys. Rev. Lett. 67, 991 (1991)10.1103/PhysRevLett.67.991] which is strictly valid for preformed channels. Particle-in-cell simulations agree with this new theory, which predicts less hosing growth than found by the hosing theory of Whittum et al.

An attempt to measure the spread of emergency medicine internationally

OBJECTIVE

To determine the feasibility of using the internet to track the spread of emergency medicine internationally.

OVERVIEW

This was an attempt to perform a descriptive cross-sectional study employing a web-based survey.

SUBJECTS

Potential respondents were identified from multiple sources.

OBSERVATIONS

The primary outcome was the response to 16 questions about EM care and the setting in which it was delivered for acute cardiac, paediatric, obstetrical illnesses and trauma. The questions were divided into six general areas and elicited for urban, semi-urban and rural settings. A series of four e-mails soliciting completion of the survey were sent to potential respondents.

ANALYSIS

Simple descriptive statistics.

RESULTS

We identified 358 potential respondents with valid e-mail addresses over a period of three years. Overall, 145 (41%) responded and 117 (33% 95% CI 28-38%) of them were complete and interpretable. There was one response from 54 and two responses from 29 countries, representing an overall response rate by country surveyed of 65% (95% CI 57-73%), but of all existing countries of only 43% (95% CI 36-50%). Based on sparse data, it appears that in urban areas, 47% (obstetrics) to 65% (paediatric) of acutely sick or injured patients are taken to an ED-equivalent. For rural areas, this range was 19% (obstetrical) to 40% (trauma). CT scans are available in 78% of urban ED-equivalents but 12% of rural ones. Haematocrits are available in 72% of rural settings. In 60% of responding nations, some type of EM training was available, and in 42% physicians went abroad to study EM.

CONCLUSIONS

A survey of international EM is challenging to achieve because of difficulty in both identifying and in contacting potential respondents. Based on sparse data, population density (urban, rural) appears to be related to both the location to which acutely ill patients are taken for their care and to the level of technology available. The specialty of EM is now recognised internationally and education in EM is common.

Effects of yogurt and bifidobacteria supplementation on the colonic microbiota in lactose-intolerant subjects

AIMS

Colonic metabolism of lactose may play a role in lactose intolerance. We investigated whether a 2-week supplementation of Bifidobacterium longum (in capsules) and a yogurt enriched with Bifidobacterium animalis could modify the composition and metabolic activities of the colonic microbiota in 11 Chinese lactose-intolerant subjects.

METHODS AND RESULTS

The numbers of total cells, total bacteria and the Eubacterium rectale/Clostridium coccoides group in faeces as measured with fluorescent in situ hybridization and the faecal beta-galactosidase activity increased significantly during supplementation. The number of Bifidobacterium showed a tendency to increase during and after supplementation. With PCR-denaturing gradient gel electrophoresis, in subjects in which B. animalis and B. longum were not detected before supplementation, both strains were present in faeces during supplementation, but disappeared after supplementation. The degree of lactose digestion in the small intestine and the oro-caecal transit time were not different before and after supplementation, whereas symptom scores after lactose challenge decreased after supplementation.

CONCLUSIONS

The results suggest that supplementation modifies the amount and metabolic activities of the colonic microbiota and alleviates symptoms in lactose-intolerant subjects. The changes in the colonic microbiota might be among the factors modified by the supplementation which lead to the alleviation of lactose intolerance.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides evidence for the possibility of managing lactose intolerance with dietary lactose (yogurt) and probiotics via modulating the colonic microbiota.

[Tracheoplasty for tracheal cuff stenosis post long-term tracheostomy]

We encountered a case of tracheal stenosis post tracheostomy, so-called cuff stenosis. A 43-year-old man with ventricular septal defect (VSD) was treated by oral endotracheal intubation because of heart-failure and pneumonia, and tracheostomy was performed. He was placed on artificial ventilation for almost 3 months. Four months after discharge, he complained of dyspnea and was treated by oral endotracheal intubation again. At that time bronchofiberscopy demonstrated severe circumferential stenosis of the trachea 4 cm from the tracheostomy spot and that was compatible with the cuff site. Although the stenotic portion was dilated by an endotracheal tube, 47-days after dilation, the portion was restenosed to almost 7 mm in diameter. Therefore, surgical treatment was necessary and tracheoplasty was performed by end-to-end suture after 2 cm (4 ring) resection of trachea. Tracheoplasty is the most reliable method of treating cuff stenosis after tracheostomy.

Surface plasmon interference excited by tightly focused laser beams

We show that interfering surface plasmon polaritons can be excited with a focused laser beam at normal incidence to a plane metal film. No protrusions or holes are needed in this excitation scheme. Depending on the axial position of the focus, the intensity distribution on the metal surface is either dominated by interferences between counterpropagating plasmons or by a two-lobe pattern characteristic of localized surface plasmon excitation. Our experiments can be accurately explained by use of the angular spectrum representation and provide a simple means for locally exciting standing surface plasmon polaritons.

Photo-induced lipid peroxidation of erythrocyte membranes by a bis-methanophosphonate fullerene

Using human erythrocyte membranes (EMs) as a model system, we have examined photo-induced lipid peroxidation by a bis-methanophosphonate fullerene (BMPF) and four other fullerene derivatives including a mono-methanophosphonic acid fullerene (MMPF), a dimalonic acid C(60) (DMA C(60)), a trimalonic acid C(60) (TMA C(60)) and a polyhydroxylated fullerene (fullerol). Lipid peroxidation was assessed as the malondialdehyde (MDA) level measured by the thiobarbituric acid assay. It was observed that BMPF increased the MDA level of EMs after irradiation in both time- and dose-dependent manners. The photo-induced activity became very significant (p<0.01) under the conditions of either the concentration of 10 microM and irradiation time of 30 min or the concentration of 5 microM and irradiation time of 60 min. Involvement of reactive oxygen species (ROS) in the activity was also examined by specific inhibitors of singlet oxygen, superoxide anions and hydroxyl radicals, respectively. While all three kinds were found responsible for the activity, the former two might play more important roles than the last one. Furthermore, the activity of BMPF was the strongest among all tested fullerene derivatives. These results indicated BMPF was a potential photosensitizer that would find application in photodynamic therapy.

A phase II study of weekly low-dose paclitaxel plus 24-hour infusion of cisplatin as first-line chemotherapy for metastatic breast cancer (MBC)

1100

Background: The dose and schedule of paclitaxel have been evolving in the past 15 years. However, the lowest effective dose of weekly paclitaxel remains unclear. In this study, we examined if a very low dose of paclitaxel can be effective in MBC. Except for the dose of paclitaxel, the chemotherapy regimen and the patient population of this study were very similar to one of our previous report (Cancer 2002; 95:2044–50). Methods: Women with chemotherapy-naïve metastatic BC, adequate performance status and organ functions were eligible. All patients received paclitaxel, 50 mg/m2 iv 1 hr on D1, 8 and 15, and cisplatin, 40 mg/m2 iv 24 hrs on D1 and 8, every 4 weeks. Patients continued this low-dose regimen until progressive disease (PD) or prohibitive toxicities occurred. Patients who had PD or stable disease (SD) without clinical benefit were shifted to paclitaxel 80 mg/m2 iv 1 hr on D1, 8 and 15, and cisplatin, 40 mg/m2 iv 24 hrs on D1 and 8, every 4 weeks. The primary endpoint was overall response rate (ORR). Simon’s optimal two-stage design (P0, P1,a, and βare 20%, 40%, 0.05, and 0.2, respectively) was adopted. More than 4 objective responses were needed in the first 13 patients, and a total of 43 patients will be enrolled. Results: After a median follow-up duration of 16.5 months, 27 patients were evaluable for response and toxicity. Their median age was 52.7 years (range: 30.1∼69.4). Twenty patients were hormone receptor (+), while 6 patients were Her-2/neu (+). A total of 121 cycles of protocol treatment were administered as of Dec. 2006. There were 0 complete response and 14 partial responses, for an ORR of 51.9%. Nine of 14 responders remain progression-free. The PFS was 9.6 months (95% of CI: 5.53∼13.67%) and the OS not reached. Grade 3–4 anemia, neutropenia, liver toxicity, thrombocytopenia, and skin toxicities were reported in 8, 6, 2, 1, and 1 patients, respectively. Neurotoxicity was common (22/27), but all were grade 1 or 2. Conclusions: The preliminary results of this study suggest that weekly low-dose paclitaxel is as effective as conventional-dose paclitaxel, and the treatment-related toxicities were more acceptable.

No significant financial relationships to disclose.

Application of pharmacodynamic assays in a phase Ia trial of Apo2L/TRAIL in patients with advanced tumors

3535

Background: Recombinant human (rh) Apo2L/TRAIL is a dual pro-poptotic receptor agonist (PARA) that induces apoptosis by binding to pro-apoptotic receptors DR4 and DR5, which recruit a death inducing signaling complex upon ligand binding. This results in activation of the effector caspase 3/7, that subsequently cleaves intracellular substrates to execute cellular apoptosis. A Phase1a trial is underway to evaluate the safety and tolerability of rhApo2L/TRAIL in patients with advanced tumors. The aim of this study was to develop and validate high-throughput pharmacodynamic assays to monitor rhApo2L/TRAIL activity in easily accessible patient samples such as serum. Methods: To monitor rhApo2L/TRAIL activity in patients, we optimized assays to measure the release of the apoptotic markers caspase 3/7, cytokeratin 18 (CK18), and genomic DNA (gDNA) in serum. Serum caspase 3/7 levels were monitored using the Caspase Glo kit, which generates a luminescent signal upon cleavage of a caspase 3/7 substrate; cleavage of the caspase substrate CK18 was measured using an optimized form of the M30 ELISA assay; gDNA was measured using a β-actin-specific TaqMan real-time PCR assay. Mice bearing Colo205 xenografts were treated with rhApo2L/TRAIL and sera were collected and assayed for apoptotic markers. Upon validating these assays, we monitored the levels of apoptotic markers in cancer patients who received rhApo2L/TRAIL. Results: We detected transient increases in apoptotic markers in mouse sera 8–24 hr after treatment with rhApo2L/TRAIL. This increase was dose-dependent and correlated with active caspase 3 detected by IHC in Colo205 tumors. In the phase Ia study, increases in serum caspase 3/7 and gDNA levels were observed in >50% of colorectal, lung and sarcoma patients evaluated. Preliminary analyses show the percentage of increase correlates using both analytes and is dose-dependent. Conclusions: These findings support the use of serum-based pharmacodynamic assays as a means to monitor rhApo2L/TRAIL activity in patients with advanced tumors. A complete analysis of all patient serum samples from the ongoing phase Ia trial will be reported.

No significant financial relationships to disclose.

The association of epidermal growth factor receptor (EGFR) polymorphisms and clinicopathological factors with skin rash on gefitinib use

18118

Background: Skin rash is the most common toxicity of EGFR-targeted therapy. Skin rash of EGFR inhibitor is associated with longer survival or tumor response. However, the clinical and genetic factors associated with this skin rash are not well understood. Methods: Fifty-two non-small-cell lung cancer patients enrolled in a prospective clinical trial of first-line gefitinib treatment were genotyped for EGFR intron 1 CA repeat polymorphism (CAn) and single nucleotide polymorphisms at promoters G-216T, C-191A, and R521K. Grade 2 to 3 skin rash within 4 weeks of treatment (early G2/3 rash) was correlated with the genotype and clinicopathological features of the patients by multivariate logistic regression. Results: Seventeen patients (32.7%) developed early G2/3 rash. In multivariate logistic regression analysis, only the CAn genotype was associated with early G2/3 rash and the effect was modified by patient age. Early G2/3 rash developed in 21% of patients with homozygous long allele (19 to 22 repeats, L) genotype (4/19), 31% of heterozygous short allele (15 to 18 repeats, S) / L genotype (8/26), and 71% of S/S genotype (5/7), respectively. The median ages of patients with early G2/3 rash and patients without early G2/3 rash were 57 years (range: 39–77) and 69 years (range: 43–86), respectively. The estimated logarithm of odds ratio (ln OR) for early G2/3 rash, as compared to S/S genotype, for S/L genotype was -0.038 multiplied by patient age (P = 0.011); and the ln OR for L/L genotype was -0.050 multiplied by patient age (P = 0.004). Fifty patients were evaluable for response. In logistic regression analysis, early G2/3 rash correlated with tumor response (P = 0.027). However, the CAn genotype was not significantly correlated with tumor response (P = 0.43). Conclusions: Homozygous short allele of EGFR CAn is more likely to develop skin rashes on gefitinib treatment. Genotyping of EGFR CAn appears to be a useful predictive marker for development of skin rashes on gefitinib use.

[Table: see text]

Preferential chemosensitivity to gemcitabine by cyclin E overexpression in human gastric cancers

21020

Background: Exploration of molecular determinants for chemosensitivity is the key element of personalized cancer therapy. Cyclin E is a major G1-phase cyclin, together with the CDK2, which mediates phosphorylation and functional inactivation of Rb protein. Cyclin E overexpression has been demonstrated in a variety of cancers, including human gastric cancers (GC), while its biologic significance in drug therapy remains unclear. Previously, we have demonstrated that cyclin D1 overexpression plays an important role in differential chemosensitivity of human GC cells (Proc Am Assoc Cancer Res 2004; 45: abstract 4888). In this study, we examine the roles between cyclin E overexpression and chemosensitivity of human GC cells. Methods: Compared human gastric cancer cells (NCI-N87) with stably transfected cells (N87-CyE), which have 2-fold overexpression of cyclin E, the IC50 for gemcitabine (2'-2'-difluoro- deoxycytidine, dFdC) was more than 1-log lower in N87-CyE (17.0 ± 2.7 nM) than N87 cells (113.7 ± 6.5 nM) by MTT colorimetric cytotoxicity assay. In contrast, the N87-CyE cells are only slightly more chemosensitive to taxanes (paclitaxel and docetaxel), and confer largely identical chemosensitivity to 5-FU, cisplatin, and irinotecan (CPT-11). We applied RNA interference (RNAi) of cyclin E to N87 cells. The stably transfected N87-CyE/RNAi cells readily confer gemcitabine resistance with the IC50 for gemcitabine of 124.5 ± 1.6 nM. Results: Gemcitabine-induced apoptosis in N87, N87-CyE, or N87-CyE/RNAi cells was shown in either caspase-3 or PARP (poly ADP-ribose polymerase) cleavage assay by Western blotting, and Annexin-V-FITC apoptosis detection by flowcytometry. The threshold concentration of gemcitabine for caspase-3 and PARP cleavage was 10–25 nM for N87-CyE, and 100–200 nM for N87 or N87-CyE/RNAi, respectively. Conclusions: Our data demonstrate that preferential chemosensitivity to gemcitabine by cyclin E overexpression in gastric cancer cells. Gemcitabine-induced apoptosis is enhanced by cyclin E overexpression, while is reduced by RNAi of cyclin E. Further studies for potential clinical use of gemcitabine in personalized chemotherapy for cyclin E or cyclin D1-overexpressing GC are warranted (supported by the grants of NHRI-CN-CA9201S, Taiwan).

No significant financial relationships to disclose.

Phase II study of weekly docetaxel and gemcitabine in relapsed patients (pts) with advanced, platinum-exposed non-small cell lung cancer (NSCLC)

18039

Background: Docetaxel (D) has, clear-cut therapeutic superiority compared to best supportive care, or ifosfamide/vinorelbine in relapsed NSCLC and, as a result, is the standard of comparison in the second line setting. In the pre-pemetrexed era, gemcitabine (G) in phase II studies also demonstrated activity in the salvage setting with favorable survival rates. We therefore mounted a phase II trial pairing these two agents in pts with progressive disease (PD) after prior platinum-based therapy. Methods: Pts with advanced NSCLC and ECOG PS 0–1 progressing either during or after prior platin-based therapy received D 40 mg/m2 days 1 and 8, in combination with G 800 mg/m2 days 1 and 8 every 3 wks. In the absence of dose limiting myelosuppression or other gr=3 toxicities, the dose of G was escalated on an intra-patient basis to 1 g/m2 days 1 and 8. Pts continued treatment until disease progression or unacceptable toxicity. Results: 35 pts were enrolled: 20 pts (57%) were male; 69% were ECOG PS 1; 57% had received prior XRT. Median age was 61 (range 30–79); median time from initial diagnosis to enrollment was 12.4 months. 170 cycles total were administered (median 4, range 1–16). Overall response rate was 23% (95% CI 12–39%). Median event free survival (EFS) was 5.7 months; median overall survival 12.5 mos; with 1 year survival rate of 51%, and 2 year survival rate 20%. Those enrolled within 12 months of initial diagnosis had poorer EFS compared to those beyond 12 months (log rank p=0.04). There were no treatment-related deaths. Typical grade = 3 toxicities included neutropenia (43%), neutropenic fever (9%) diarrhea (6%), pneumonitis (9%), LFT elevations (9%) and dermatitis (9%), including nail changes. Conclusions: Combination docetaxel and gemcitabine administered days 1 and 8 every 3 weeks in good performance NSCLC pts with PD after/during platinum-based therapy appears encouraging, and presents a viable option in this population. Proof of benefit vs. docetaxel alone requires phase III testing.

No significant financial relationships to disclose.

E2F1 overexpression associated with TS and survivin gene expressions in non-small cell lung cancer

7669

Background: The thymidylate synthase (TS) expression is related to 5-FU sensitivity. The survivin expression is associated with tumor apoptosis, an indicator to predict the efficacy of chemotherapy. Recently, TS and Survivin have been reported to be E2F1 target genes. We investigate the clinical significance of the E2F1 gene expression in relation to gene expressions of TS and Survivin among non-small cell lung cancer (NSCLC). Methods: One hundred and twenty-seven NSCLC patients were investigated. Quantitative RT-PCR was performed to evaluate gene expressions of E2F1, TS, and survivin. The Ki-67 proliferation index and the apoptotic index using TUNEL method were also evaluated. Results: The E2F1 gene expression was significantly higher in stage II to III tumors than in stage I tumors (p=0.006). The E2F1 gene expression significantly correlated with the Ki-67 proliferation index (p<0.001), while no correlation was observed between the E2F1 gene expression and the apoptotic index. Regarding E2F1-target genes, the E2F1 gene expression significantly correlated with the TS gene expression (p<0.001). The E2F1 gene expression also significantly correlated with the survivin gene expression (p<0.001). The TS expression and the survivin expression significantly correlated with the Ki-67 proliferation index (p<0.001 and p<0.001, respectively). There was a significant inverse relationship between the survivin expression and the apoptotic index (p<0.001). The overall survival was significantly lower in patients with high-E2F1 tumors than in those with low-E2F1 tumors (p=0.002), especially among patients with stage II to III NSCLCs (p=0.018). The Cox regression analysis demonstrated that the E2F1 status was a significant prognostic factor for NSCLC patients (p=0.026). Conclusions: The present study revealed the E2F1 gene expression to correlate with TS and survivin gene expressions, and tumor proliferation. E2F1 overexpression could occur to produce more aggressive tumors with high proliferation rate and chemo-resistance during progression of NSCLCs. The suppression of E2F1 by RNA interference would be a useful strategy for cancer gene therapy.

No significant financial relationships to disclose.

A missense polymorphism in porcine interferon-gamma cDNA affects antiviral activity of the protein variant

We determined the interferon-γ (IFN-γ) cDNA sequence from three porcine breeds, Duroc, Landrance/Duroc hybrid, and Landrance breeds. Five single nucleotide polymorphisms (SNPs) of porcine IFN-γ (PoIFN-γ) were identified, respectively, at positions 269 (A/G), 376 (C/T), 426 (T/C), and 465 (T/C) of the coding sequence in Landrance/Duroc hybrid, and at position 251 (A/G) in Landrance breed. Among them, A269G and A251G polymorphisms resulted in Q67R and K61R replacements in the mature protein. PoIFN-γ cDNAs of Duroc breed (PoIFN-γ-W) and Landrance/Duroc hybrid (PoIFN-γ-M), which, respectively, encoded Q67 and R67, were introduced into a prokaryotic expression vector pET32 to express recombinant PoIFN-γ-W (rPoIFN-γ-W) and rPoIFN-γ-M protein variants in Escherichia coli. The identity of both protein variants was further confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We then compared bioactivities of these two recombinant proteins. Although both recombinant protein variants exhibited comparable activities in antiproliferation of PK-15 cells and in nitric oxide (NO) induction of porcine peripheral monocytes, antiviral activity of rPoIFN-γ-W protein was significantly higher (P < 0.001) than that of rPoIFN-γ-M protein in a plaque inhibition assay using pseudorabies virus (PRV). IC50 values of rPoIFN-γ-W and rPoIFN-γ-M protein in anti-PRV assay were determined as 5.3 ± 1.3 and 9.3 ± 4.3 nM, respectively.

In conclusion, we have identified five novel SNPs in PoIFN-γ cDNA, including two missense polymorphisms that result in Q67R and K61R replacements. Our results further demonstrate that Q67R can markedly reduce antiviral activity of the PoIFN-γ protein. This is the first report that shows the functional SNP in the coding region of IFN-γ. In the future, it is imperative to determine whether Q67R replacement in IFN-γ may have disease association.

Ionization-induced electron trapping in ultrarelativistic plasma wakes

The onset of trapping of electrons born inside a highly relativistic, 3D beam-driven plasma wake is investigated. Trapping occurs in the transition regions of a Li plasma confined by He gas. Li plasma electrons support the wake, and higher ionization potential He atoms are ionized as the beam is focused by Li ions and can be trapped. As the wake amplitude is increased, the onset of trapping is observed. Some electrons gain up to 7.6 GeV in a 30.5 cm plasma. The experimentally inferred trapping threshold is at a wake amplitude of 36 GV/m, in good agreement with an analytical model and PIC simulations.

Bacterial inactivation using a low-temperature atmospheric plasma brush sustained with argon gas

This study investigated the bacterial inactivation/sterilization effects of a new atmospheric plasma source, which is a brush-shaped argon glow discharge created under 1 atm pressure. Such an atmospheric plasma brush requires extremely low power of less than 20 W to operate; and therefore is essentially a low-temperature discharge as confirmed by gas-phase temperature measurements. Two bacteria, Escherichia coli (E. coli) and Micrococcus luteus (M. luteus), seeded in various media were subjected to plasma treatment and their survivability was examined. It was found that such argon atmospheric plasma brush is very effective in destruction of the bacteria cells. With nutrient broth and standard methods agar as supporting media, a cell reduction in a level of 6 orders of magnitude was observed for E. coli within 3-4 min plasma treatment. A similar level of cell reduction was also observed for M. luteus in the two media with 2 or 3 min plasma treatment. The plasma treatment effects on the bacteria cell structures were also examined using scanning electron microscopy and the cell structure damages due to the plasma exposure were observed on both bacteria. The possible sterilization mechanism of the argon plasmas is also discussed in this article.

Passive derivation of basic walker-assisted gait characteristics from measured forces and moments

This work describes a method that passively assesses basic walker-assisted gait characteristic, including heel strikes, toe-off events, as well as stride time, double support and right & left single support phases using only force-moment measurements from the walker's handles. The passively derived gait characteristics were validated against motion capture gait analysis and showed good correlations. This research is part of an effort that aims to identify user intent, from measuring forces and moments exerted on the handles of the walker as well as from perceiving the environment, and to incorporate identified intent into a passive shared steering control system for the walker. The primary focus of the work leading to This work is to identify the double support phase, and to engage the steering control at the beginning of this phase to maximize the user's stability. However, the application of the method presented and the instrumented walker can be extended to longitudinal outside the lab Gait assessment.