On chip cell separator using magnetic bead-based enrichment and depletion of various surface markers

This paper presents an on-chip magnetic cell sorting system for the sorting of cells based on a variety of surface markers. A polymer lab on a chip integrated with an electroplated array of Ni/Fe permalloy has been designed, fabricated, and characterized for the separation of cell substitutes at a variety of flow rates and incubation times. The system sequentially labels cell substitutes with magnetic beads and sorts them, repeating this process to sort for a variety of surface markers. Flow rates and incubation times were varied to characterize the system and produce the best combination of high specific capture and low nonspecific capture. The separation system developed on polymer is selective and efficient while being low cost, portable, and fabricated in a modular structure that can be integrated with other cell handling processes.     

Medication overuse headache: a critical review of end points in recent follow-up studies

No guidelines for performing and presenting the results of studies on patients with medication overuse headache (MOH) exist. The aim of this study was to review long-term outcome measures in follow-up studies published in 2006 or later. We included MOH studies with >6 months duration presenting a minimum of one predefined end point. In total, nine studies were identified. The 1,589 MOH patients (22% men) had an overall mean frequency of 25.3 headache days/month at baseline. Headache days/month at the end of follow-up was reported in six studies (mean 13.8 days/month). The decrease was more pronounced for studies including patients with migraine only (−14.6 days/month) compared to studies with the original diagnoses of migraine and tension-type headache (−9.2 days/month). Six studies reported relapse rate (mean of 26%) and/or responder rate (mean of 28%). Medication days/month and change in headache index at the end of follow-up were reported in only one and two of nine studies, respectively. The present review demonstrated a lack of uniform end points used in recently published follow-up studies. Guidelines for presenting follow-up data on MOH are needed and we propose end points such as headache days/month, medication days/month, relapse rate and responder rate defined as ≥50% reduction of headache frequency and/or headache index from baseline.     

Role of semi–quantitative dynamic contrast–enhanced MR imaging in characterization and grading of prostate cancer

ObjectiveThe study retrospectively assessed the diagnostic value of semi-quantitative dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) in characterization and grading of prostate cancer, with correlation to histopathological analysis.Materials and methods161 consecutive patients with prostate cancer underwent DCE MRI. 430 lesions, including 200 cancers with Gleason grade (GG) of 6 (n = 25), 7 (n = 112) and 8 or higher (n = 63); 80 benign hyperplasia; and 150 healthy tissues were assessed using a histology–MRI correlation. Time–intensity curve types between two radiologists and kinetic parameters (C_peak, time to peak, wash-in and wash-out) were compared in the different tissue types and GGs. Receiver operating characteristic curve analysis was performed to assess for each parameter to differentiate cancer from benign hyperplasia or healthy tissue, and GG 8 or higher from GG 6 or 7.ResultsType 2 was the prevalent assigned curve type. Inter-radiologist agreement for the curve types was excellent. Cancer and GG 8 or higher significantly showed a higher C_peak and faster wash-in compared to healthy tissue and GG 6. Only wash-in significantly differentiated cancer from healthy tissue, and GG 8 or higher from GG 6, having an area under the curve (AUC) of 0.755 and 0.815 respectively. Wash-in for the combined parameters revealed AUCs of 0.791 and 0.839 in two (C_peak) parameters, and AUCs of 0.862 and 0.891 in three (C_peak and wash-out) parameters.ConclusionSemi-quantitative parameters can differentiate cancer from benign hyperplasia and healthy tissue. Wash-in is the most accurate differentiation parameter of cancer foci and GG 8 or higher.     

Noninvasive finding of local repolarization changes in the heart using dipole models and simplified torso geometry

Two inverse methods using dipole models for noninvasive assessment of local repolarization changes were investigated and compared in the simulation study. Lesions with changed repolarization were modeled by shortening of the action potential durations in ventricular regions typically influenced by occlusion of coronary arteries. Corresponding body surface potentials were computed using a multiple dipole model of the cardiac generator and an inhomogeneous torso model. Position of each lesion was then estimated by an inverse solution to a single dipole and to a group of five neighbouring dipoles. For both methods the lesion localization error was evaluated and its dependence on the lesion size and the noise in input data was studied. When no noise was present in the input data, the use of the inverse method to a group of dipoles instead of a single dipole resulted in an unsubstantial reduction of the mean localization error of small lesions from 0.6 to 0.5 cm. For medium and especially for large lesions the mean localization errors decreased significantly from 1.1 to 0.6 cm and from 2.3 to 1.0 cm, respectively. The inverse solution to a group of five dipoles was more sensitive to noise. However, for large lesions it still gave better results than the solution to a single dipole if the signal to noise ratio was higher than 30 dB.     

游离髂腹股沟皮瓣在足部创面的应用

目的探讨游离髂腹股沟皮瓣修复足外伤软组织缺损的临床效果。方法应用游离髂腹股沟皮瓣修复足外伤软组织缺损12例，缺损面积：6cm×13cm-10cm×20cm，平均8cm×16cm，其中软组织感染5例。入院清创、骨折内固定，感染病例先行负压封闭引流（VSD）治疗1周，待感染控制后切取皮瓣修复创面。结果12例皮瓣全部成活．创面一期愈合，随访3个月～1年，疗效满意，皮瓣质地柔软，外观臃肿不明显，供区愈合良好，仅留有线状瘢痕。根据下肢负重是否疼痛、关节活动度及恢复工作等指标评价下肢肢体功能．优良率为85％。结论足外伤软组织缺损行游离腹股沟皮瓣修复可获得较满意疗效。     

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??Objective    To compare the effects of pure titanium and conventional steel ultrasonic scaler tips on titanium surface and evaluate the adhesion strength of human periodontal ligament cells??hPDLCs??on the titanium surface treated by the two different tips. Methods    Totally 60 smooth titanium discs were used in this research. The discs were randomly divided into five groups??each of which contained 12 discs. Ti10 group??discs were scaled for 10s with pure titanium tip??Ti30 group??discs were scaled for 30s with pure titanium tip??Cv10 group??discs were scaled for 10s with conventional steel tip??Cv30 group??discs were scaled for 30s with conventional steel tip. Control group??discs were not scaled. After the treatment according to the protocols??the morphology and roughness of the discs were evaluated by scanning electron microscope??SEM??and profilometer separately. In order to test the biocompatibility of the treated titanium discs??hPDLCs were co-cultured with those discs for 12 hours??and the cell toxicity of treated discs and the adhesion strength of hPDLCs on titanium discs was calculated with CCK-8 method. Results       SEM results showed that Ti10 group had less morphological changes than Cv10 group and this change was highly consistent with the profilometer results which also showed that the roughness of titanium at Ti10 group was significantly lower than Cv10 group??P < 0.05??. However??if the scaling time increased to 30 seconds??there were no statistical difference among groups. There were no significant difference among groups for the adhesion strength of hPDLCs after being treated by different scaler tips and no toxicity was found. Conclusion    Pure titanium ultrasonic scaler tips are better than conventional ultrasonic scaler tip with respect to the protection of titanium surface??although there were no significant differences in the promotion of cell adhesion.     

[Online First]Improvement of human embryonic stem cell-derived retinal pigment epithelium cell adhesion, maturation， and function through coating with truncated recombinant human vitronectin

AIM: To explore an xeno-free and defined coating substrate suitable for the culture of H9 human embryonic stem cell-derived retinal pigment epithelial (hES-RPE) cells in vitro, and compare the behaviors and functions of hES-RPE cells on two culture substrates, laminin521 (LN-521) and truncated recombinant human vitronectin (VTN-N). METHODS: hES-RPE cells were used in the experiment. The abilities of LN-521 and VTN-N at different concentrations to adhere to hES-RPE cells were compared with a high-content imaging system. Quantitative real-time polymerase chain reaction was used to evaluate RPE-specific gene expression levels midway (day 10) and at the end (day 20) of the time course. Cell polarity was observed by immunofluorescent staining for apical and basal markers of the RPE. The phagocytic ability of hES-RPE cells was identified by flow cytometry and immunofluorescence. RESULTS: The cell adhesion assay showed that the ability of LN-521 to adhere to hES-RPE cells was dose-dependent. With increasing coating concentration, an increasing number of cells attached to the surface of LN-521-coated wells. In contrast, VTN-N presented a strong adhesive ability even at a low concentration. The optimal concentration of LN-521 and VTN-N required to coat and adhesion to hES-RPE cells were 2 and 0.25 µg/cm2, respectively. Furthermore, both LN-521 and VTN-N could facilitate adoption of the desired cobblestone cellular morphology with tight junction and showed polarity by the hES-RPE cells. However, hES-RPE cells cultivated in VTN-N had a greater phagocytic ability, and it took less time for these hES-RPE cells to mature. CONCLUSION: VTN-N is a more suitable coating substrate for cultivating hES-RPE cells.     

Surface model of the gastrointestinal tract constructed from the Visible Korean

Most currently available three‐dimensional surface models of human anatomic structures have been artistically created to reflect the anatomy being portrayed. We have recently undertaken, as part of our Visible Korean studies, to build objective surface models based on cross‐sectional images of actual human anatomy. Objective of the present study was to elaborate surface models of the GI tract and neighboring structures that are helpful to medical simulation. The GI tract from stomach to anal canal was outlined and reconstructed from sectioned images of the Visible Korean (acomputer database containing the digitized transverse sectional images of a 33‐year‐old Korean man). The outlining procedure was supported by computational filtering and interpolation using commercially available software. The GI tract was divided into several parts, and each of these parts was surface reconstructed and then united with neighboring parts to produce a surface model of the complete GI tract. Surface models of about 100 neighboring structures were also prepared. The surface models produced will hopefully facilitate the development of interactive simulations for a variety of virtual abdominal surgical procedures or other educational programs. In addition, it is hoped that the improved outlining and surface reconstruction techniques described will encourage other researchers to construct similar surface models based on images obtained from different subjects. Clin. Anat. 22:601–609, 2009. © 2009 Wiley‐Liss, Inc.     

Hepatitis A virus in surface water in South Africa: what are the risks?

The aim of this study was to assess the potential risk of infection constituted by HAV to persons using surface dam and river water for domestic and recreational purposes. It estimates the potential risk using a deterministic exponential risk assessment model with mean values and conservative assumptions. Hepatitis A virus was detected in 17.5% of river and 14.9% of dam water samples tested. The number of indicator organisms in these sources exceeded drinking and recreational water quality guidelines set by the United States Environmental Protection Agency (US EPA), indicating possible health risks to recreational water users. Based on the available data and taking all the assumptions into consideration, the probability of infection (P_inf) to the higher socio-economic population using the river water for recreational purposes was 1.1 × 10^-3 per day and 3.3 × 10^-1 per annum if 100 ml was ingested per day. For recreation in the dam water the P_inf value was 1.2 × 10^-4 per day and 4.2 × 10^-2 per annum. For the lower socio-economic population, risk values for drinking purposes (2 L day^-1) were ten-fold greater. These surface waters therefore did not conform to the US EPA guidelines of 1 infection per 10,000 consumers per year for drinking water or eight gastrointestinal illnesses per 1,000 bathers per day in environmental waters used for recreational purposes. This is the first risk assessment study addressing the risk of infection by HAV in surface water to different socio-economic populations in South Africa.