Scalable single-cell profiling of chromatin modifications with sciCUT&Tag

Cleavage under targets and tagmentation (CUT&Tag) is an antibody-directed in situ chromatin profiling strategy that is rapidly replacing immune precipitation-based methods, such as chromatin immunoprecipitation-sequencing. The efficiency of the method enables chromatin profiling in single cells but is limited by the numbers of cells that can be profiled. Here, we describe a combinatorial barcoding strategy for CUT&Tag that harnesses a nanowell dispenser for simple, high-resolution, high-throughput, single-cell chromatin profiling. In this single-cell combinatorial indexing CUT&Tag (sciCUT&Tag) protocol, lightly cross-linked nuclei are bound to magnetic beads and incubated with primary and secondary antibodies in bulk and then arrayed in a 96-well plate for a first round of cellular indexing by antibody-directed Tn5 tagmentation. The sample is then repooled, mixed and arrayed across 5,184 nanowells at a density of 12-24 nuclei per well for a second round of cellular indexing during PCR amplification of the sequencing-ready library. This protocol can be completed in 1.5 days by a research technician, and we illustrate the optimized protocol by profiling histone modifications associated with developmental gene repression (H3K27me3) as well as transcriptional activation (H3K4me1-2-3) in human peripheral blood mononuclear cells and use single-nucleotide polymorphisms to facilitate collision removal. We have also used sciCUT&Tag for simultaneous profiling of multiple chromatin epitopes in single cells. The reduced cost, improved resolution and scalability of sciCUT&Tag make it an attractive platform to profile chromatin features in single cells.

[Animal study on left bundle branch current of injury and anatomic location of leads in His-purkinje conduction system pacing]

Objective: Explore the relationship between tip of the left bundle branch pacing lead and anatomic location of left bundle branch as well as the mechanism of left bundle branch current of injury. To clarify the clinical value of left bundle branch current of injury during operation. Methods: The pacing leads were implanted in the hearts of two living swines. Intraoperative electrophysiological study confirmed that the left bundle branch or only the deep left ventricular septum was captured at low output. Immediately after operation, the gross specimen of swine hearts was stained with iodine to observe the gross distribution of His-purkinje conduction system on the left ventricular endocardium and its relationship with the leads. Subsequently, the swine hearts were fixed with formalin solution, and the pacing leads were removed after the positions were marked. The swine hearts were then sectioned and stained with Masson and Goldner trichrome, and the relationship between the anatomic location of the conduction system and the tip of the lead was observed under a light microscope. Results: After iodine staining of the specimen, the His-purkinje conduction system was observed with the naked eye in a net-like distribution, and the lead tip was screwed deeply and fixed in the left bundle branch area of the left ventricular subendocardium in the ventricular septum. Masson and Goldner trichrome staining showed that left bundle branch pacing lead directly passed through the left bundle branch when there was left bundle branch potential with left bundle branch current of injury, while it was not directly contact the left bundle branch when there was left bundle branch potential without left bundle branch current of injury. Conclusion: The left bundle branch current of injury observed on intracardiac electrocardiogram during His-purkinje conduction system pacing suggests that the pacing lead directly contacted the conduction bundle or its branches, therefore, the captured threshold was relatively low. Left bundle branch current of injury can be used as an important anatomic and electrophysiological evidence of left bundle branch capture.

Accelerating TB diagnosis during the COVID-19 pandemic

SETTING: The COVID-19 pandemic has caused significant disruption worldwide to economies and healthcare systems, even those with well-developed infrastructure.OBJECTIVE: To examine the effects of COVID-19 on TB diagnosis in Singapore, and to identify any factors that could facilitate early detection of TB among persons screened.DESIGN: To assess the impact of testing and diagnosis of the pandemic on TB, the number of TB-related tests from January 2018 to December 2020 were collected. We also conducted a retrospective case-control study of all adult patients admitted for COVID-19, TB or coinfection from 23 January to 31 May 2020.RESULTS: Nationwide testing for TB from 2018 to 2020 increased by 24.2%. We analysed 253 adult inpatients, of whom 107 (42.3%) were diagnosed with COVID-19, 134 (53.0%) had TB, while 12 (4.7%) had co-infection. Patients with TB were more likely to have chest X-ray abnormalities than those with COVID-19 (89.9% vs. 76.0%; P < 0.01). Patients with TB were more likely to have prolonged cough vs. those with COVID-19 infection (28 vs. 5 days; P < 0.01).CONCLUSION: Early screening for TB, even among patients with COVID-19, could lead to earlier diagnosis and treatment, thereby breaking the chain of transmission.

Clinical standards for the diagnosis, treatment and prevention of TB infection

BACKGROUND: Tuberculosis (TB) preventive therapy (TPT) decreases the risk of developing TB disease and its associated morbidity and mortality. The aim of these clinical standards is to guide the assessment, management of TB infection (TBI) and implementation of TPT.METHODS: A panel of global experts in the field of TB care was identified; 41 participated in a Delphi process. A 5-point Likert scale was used to score the initial standards. After rounds of revision, the document was approved with 100% agreement.RESULTS: Eight clinical standards were defined: Standard 1, all individuals belonging to at-risk groups for TB should undergo testing for TBI; Standard 2, all individual candidates for TPT (including caregivers of children) should undergo a counselling/health education session; Standard 3, testing for TBI: timing and test of choice should be optimised; Standard 4, TB disease should be excluded prior to initiation of TPT; Standard 5, all candidates for TPT should undergo a set of baseline examinations; Standard 6, all individuals initiating TPT should receive one of the recommended regimens; Standard 7, all individuals who have started TPT should be monitored; Standard 8, a TBI screening and testing register should be kept to inform the cascade of care.CONCLUSION: This is the first consensus-based set of Clinical Standards for TBI. This document guides clinicians, programme managers and public health officers in planning and implementing adequate measures to assess and manage TBI.

Single-cell CUT&Tag analysis of chromatin modifications in differentiation and tumor progression

Methods for quantifying gene expression¹ and chromatin accessibility² in single cells are well established, but single-cell analysis of chromatin regions with specific histone modifications has been technically challenging. In this study, we adapted the CUT&Tag method³ to scalable nanowell and droplet-based single-cell platforms to profile chromatin landscapes in single cells (scCUT&Tag) from complex tissues and during the differentiation of human embryonic stem cells. We focused on profiling polycomb group (PcG) silenced regions marked by histone H3 Lys27 trimethylation (H3K27me3) in single cells as an orthogonal approach to chromatin accessibility for identifying cell states. We show that scCUT&Tag profiling of H3K27me3 distinguishes cell types in human blood and allows the generation of cell-type-specific PcG landscapes from heterogeneous tissues. Furthermore, we used scCUT&Tag to profile H3K27me3 in a patient with a brain tumor before and after treatment, identifying cell types in the tumor microenvironment and heterogeneity in PcG activity in the primary sample and after treatment.

Identification of potential crucial genes associated with vasculogenic mimicry in human osteosarcoma based on gene expression profile

We previously reported the presence of vasculogenic mimicry (VM) in human osteosarcoma. However, the mechanistic basis of osteosarcoma VM remains unclear. Three hundred eighty-one upregulated differentially expressed genes (DEGs) and 526 downregulated DEGs between human osteosarcoma cell line 143B and HOS cell exposed to Matrigel were screened out by microarray. GO categories such as "cell adhesion", "angiogenesis" were enriched in 143B group. PATHWAY analysis showed enriched TGF-beta, Wnt and VEGF signaling pathway in 143B group. The hub gene ITGA2 in signal-network of DEGs exhibited pro-VM and pro-metastasis effect. Our study provides fundamental data for further studies regarding molecules involved in osteosarcoma VM.

P4528Feasibility and safety of left bundle branch area pacing by transvenous approach through the interventricular septum in patients with left bundle branch block

Background

His bundle pacing (HBP) has been shown to correct left bundle branch block (LBBB), however it often requires high pacing output and the success rate is variable.

Objective

To assess the feasibility and safety of left bundle branch area pacing (LBBAP) in patients with LBBB.

Methods

From Apr 2014 to Aug 2018, patients with LBBB from multicenters indicated for CRT or pacing therapy were included. LBBAP was performed by advancing the MDT 3830 lead deep into the septum about 1 cm distal to the His bundle region (Figure 1F). Pacing characteristics, success rate, threshold and R-wave amplitude were assessed.

Results

A total of 94 patients aged 68.3±10.7 y with the native QRS duration of 167.2±17.2 ms were included. In 92 patients, LBBAP was successfully achieved and demonstrated RBBB pattern during unipolar tip pacing (UTP), with the paced QRS duration of 116.4±12.6ms (Figure 1C). Fusion of LBBAP and native conduction via the RBB eliminated RBBB and resulted in an average QRS duration of 103.2±10.1 ms (Figure 1D). LBB potential could be recorded from the LBB lead during correction of LBBB by HBP in 21 patients who used two leads method (His lead and LBB lead, Figure 1B). Output dependent selective and non-selective LBBAP were demonstrated in 48 patients (Figure 1C, D). The LBB capture threshold by UTP was 0.53±0.18V/0.5ms at acute and 0.62±0.17V/0.5ms at 6 months and 0.65±0.2V/0.5ms at 1 year. The R-wave amplitude were 11.4±5.2mV, 12.4±5.8mV and 12.0±5.8mV at acute, 6 month and 1 year. During follow-up, only one patient had an increase in LBB capture threshold to 2.5V/0.5ms at 3 months and there were no other complications such as dislodgment, infections, embolism or stroke associated with the implantation.

Conclusion

Permanent LBBAP is feasible and safe in patients with LBBB.

P6548Left bundle branch area pacing in patients with atrioventricular block

Background

The application of His bundle pacing (HBP) on patients with distal AV block should be of concern.Left bundle branch Aera pacing (LBBA pacing), pacing immediately beyond the site of block will be considered.

Purpose

To access the clinical benefits and safety of LBBA pacing in patients with atrioventricular (AV) block.

Methods

One hundred and thiry nine patients diagnosed with AVB were included. The Select Secure lead (model 3830; Medtronic) was used. Characteristics of LBB capture are summarized as following: 1) The paced QRS morphology of RBBB pattern during unipolar tip pacing; 2) Usually, LBB potential could be recorded; 3) If higher output pacing shortened the times abruptly and the times remain constant. Pacing parameters (threshold, R-wave amplitude and impedance) and Echocardiographic measurements were assessed during follow-up.

Results

All patients were success achieved LBBA pacing. The detailed baseline characteristic and follow-up were shown in the Table. Threshold, R-wave amplitude and impedance remained stable during follow -up. Echocardiographic measurements showed that LBB pacing did not affect the cardiac function. There was no LV septum penetration and dislodgment.

Conclusion

LBBA pacing had ideal pacing parameters and preserve cardiac function and may be an excellent alternative to HBP or RVP.

Acknowledgement/Funding

Key R&D Program of Zhejiang (2019C03012), Major Project of the Science and Technology of Wenzhou (ZS2017010)

CUT&Tag for efficient epigenomic profiling of small samples and single cells

Many chromatin features play critical roles in regulating gene expression. A complete understanding of gene regulation will require the mapping of specific chromatin features in small samples of cells at high resolution. Here we describe Cleavage Under Targets and Tagmentation (CUT&Tag), an enzyme-tethering strategy that provides efficient high-resolution sequencing libraries for profiling diverse chromatin components. In CUT&Tag, a chromatin protein is bound in situ by a specific antibody, which then tethers a protein A-Tn5 transposase fusion protein. Activation of the transposase efficiently generates fragment libraries with high resolution and exceptionally low background. All steps from live cells to sequencing-ready libraries can be performed in a single tube on the benchtop or a microwell in a high-throughput pipeline, and the entire procedure can be performed in one day. We demonstrate the utility of CUT&Tag by profiling histone modifications, RNA Polymerase II and transcription factors on low cell numbers and single cells.

[The ratio of tuberculosis-specific antigen to phytohemagglutinin in T-SPOT assay in the diagnosis of active tuberculosis]

Objective: The aim of this study was to determine the performance of the ratio of tuberculosis-specific antigen (TBAg) to phytohemagglutinin (PHA) (TBAg/PHA ratio) in T-SPOT assay in the diagnosis of active tuberculosis (ATB). Methods: Between January 2014 and January 2017, 378 Mycobacterium tuberculosis (MTB) culture positive patients (268 cases of pulmonary tuberculosis, 110 extra-pulmonary tuberculosis) and 824 healthy individuals were recruited from Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology. T-SPOT assay was performed and TBAg/PHA ratio was calculated in all the participants. To validate the study, another group of 223 MTB culture positive TB patients with positive T-SPOT results were recruited from Guangzhou Chest Hospital between January 2017 and December 2017. This was a retrospective case-control study and differences between groups were analyzed using the Mann-Whitney U-test. Results: Of the 378 culture positive ATB patients, 344 patients had positive T-SPOT results. Of the 824 healthy individuals, 204 individuals had positive T-SPOT results. Using healthy individuals as the control group, the sensitivity and specificity of T-SPOT assay in the diagnosis of ATB were 91.0% (344/378) and 75.2% (620/824). Directly using T-SPOT results had a limited accuracy in distinguishing ATB from latent tuberculosis infection (LTBI). The area under the receiver operating characteristic (ROC) curve was between 0.7 and 0.8. However, a further calculation of the TBAg/PHA ratio showed a better performance than TBAg in distinguishing these two conditions, and the area under the ROC curve was 0.881 (95% CI: 0.853-0.909). If using the threshold value of 0.234, the sensitivity and specificity of the TBAg/PHA ratio in distinguishing ATB from LTBI were 69.5% (239/344) and 94.12% (192/204). The validation data showed that the performance of the TBAg/PHA ratio in distinguishing ATB from LTBI was also satisfactory, and the area under the ROC curve was 0.901 (95% CI: 0.872-0.931). Furthermore, the TBAg/PHA ratio had an important role in the diagnosis of extra-pulmonary tuberculosis. If using the threshold value of 0.234, the sensitivity and specificity of the TBAg/PHA ratio in the diagnosis of extra-pulmonary tuberculosis were 79.2% (76/96) and 94.1% (192/204). The area under the ROC curve was 0.932 (95% CI: 0.897-0.967). Conclusions: The TBAg/PHA ratio in T-SPOT assay was better than directly using T-SPOT results in distinguishing ATB from LTBI. This ratio also showed a potential use in the diagnosis of extra-pulmonary tuberculosis.

Automated in situ chromatin profiling efficiently resolves cell types and gene regulatory programs

BACKGROUND

Our understanding of eukaryotic gene regulation is limited by the complexity of protein-DNA interactions that comprise the chromatin landscape and by inefficient methods for characterizing these interactions. We recently introduced CUT&RUN, an antibody-targeted nuclease cleavage method that profiles DNA-binding proteins, histones and chromatin-modifying proteins in situ with exceptional sensitivity and resolution.

RESULTS

Here, we describe an automated CUT&RUN platform and apply it to characterize the chromatin landscapes of human cells. We find that automated CUT&RUN profiles of histone modifications crisply demarcate active and repressed chromatin regions, and we develop a continuous metric to identify cell-type-specific promoter and enhancer activities. We test the ability of automated CUT&RUN to profile frozen tumor samples and find that our method readily distinguishes two pediatric glioma xenografts by their subtype-specific gene expression programs.

CONCLUSIONS

The easy, cost-effective workflow makes automated CUT&RUN an attractive tool for high-throughput characterization of cell types and patient samples.

[Efficacy of standardized sublingual immunotherapy of allergic asthma with rhinitis in children between different age groups]

Objective:The aim of this study is to evaluate the efficacy of standardized sublingual immunotherapy of allergic asthma with rhinitis in children between two different age groups. Method:Retrospective analysis of 250 patients with allergic asthma and rhinitis who received SLIT treatment. According to the age divided into younger children group (aged 3-6 years, 128 patients) and older children group (aged 7-13 years, 122 patients). Evaluate the asthma daytime, nocturnal symptom, medication score, VAS score and pulmonary function FEV1, PEF% level and rhinitis symptom and medication score before and after treatment of two groups of children. Result:The DASS, NASS, TAMS, VAS, FEV1, PEF, TNSS, TRMS had continuously improved significantly after SLIT for half a year, 1 year and 2 years in two groups as compared with baseline (P<0.05). The treatment after 1 year and 2 years, curative effect strengthened continuously, and TAMS, VAS, TNSS and TRMS further reduced. After treatment of each point in time, only at SLIT treatment after half a year, the TAMS, VAS score of younger children group was lower than of older children group (Z values were 4.58 and 4.58, P<0.05). The rest of the indicators were no statistical significance difference between the two age groups (P>0.05). Conclusion:Sub-lingual immunotherapy with Dermatophagoides farinae drops in younger children and older children allergic with asthma and rhinitis can play a significant and similar effect.

[An analysis of the subcutaneous immunotherapy on the pulmonary function and symptoms of asthma and rhinitis in children]

Objective:To evaluate the effect of subcutaneous immunotherapy on allergic asthma and rhinitis in children.Method:A prospective study was adopted to analysis 3 years SCIT treatment of 144 cases of children with allergic asthma and rhinitis. Before and after SCIT treatment for 1 year, 2 and 3 years, FEV1, daytime and night symptoms of asthma and rhinitis were evaluated.Result:After 3 years of SCIT treatment, the FEV1 had significantly increased (F= 243.05, P< 0.01), and with the duration of the treatment was further improvement (P< 0.01). Compared with the baseline, treatment 1 year in daytime, nighttime symptoms scores of asthma and nighttime symptoms scores of rhinitis had significantly reduced (P< 0.01). All symptoms were reduced further by 2 years of treatment (P< 0.01) compared with 1 year. Compared with the 2 years of treatment, daytime symptoms of asthma and rhinitis of 3 years SCIT treatment was improved significantly (P< 0.05).Conclusion:Subcutaneous immunotherapy with 3 years in children allergic with asthma and rhinitis can play a significant effect.

[Experimental study of using chitosan nerve conduit combined with PRP to repair facial nerve defect]

Objective:The purpose of this study was to produce chitosan nerve conduit in order to investigate the feasibility of chitosan nerve conduit combined with autologous platelet-rich plasma (PRP) for repairing facial nerve defects.Method:Forty New Zealand white rabbits were randomly divided into four groups (n=10 in each group).Establishment of the facial nerve defect model of the upper buccal branches was placed in the nerve regeneration catheter and injected with the same amount of PRP and saline. The PRP was injected into the chitosan nerve conduit as group A. The physiological saline was injected into the chitosan nerve conduit as group B. The physiological saline was injected into the silicone tube as group C. The PRP was injected into the silicone tube as group D. Eight weeks later,facial nerve gross observation,facial nerve electrophysiological tests,histological observation,image analysis,valuation of nerve regeneration recovery were detected.Result:Five patients were lost to follow up (all five in the modified Semont group),and three patients failed to complete treatment (all three in the Epley group). The sequelae at the 3rd day and one week after modified Semont maneuver were 27 and 9,while 41 and 15 in Epley group. The efficacy rates at the 3rd day and one week after modified Semont maneuver were 91.7% and 98.3%,and 91.9% and 96.8% in Epley group retrospectively. The sequelae and short-term effective rate of patients in modified Semont group was no difference when compared with that in Epley group (P>0.05).Conclusion:The chitosan nerve conduit combined with PRP has a certain effect on the repair of facial nerve defects and is expected to be applied to the repair of clinical facial nerve defects.

[Electrocardiographic characteristics of idiopathic ventricular arrhythmias originating from the tricuspid annulus regions]

Object: To explore the electrocardiographic characteristics of ventricular arrhythmias (VAs) originating from tricuspid annulus region. Methods: Present study included 169 consecutive patients undergoing catheter ablation of VAs from tricuspid annulus origin in our department from August 2007 to September 2016. Based on the origin sites, the patients were divided into two subgroups, the free wall group (81 cases) and septal wall group (88 cases). Based on the location, patients in the free wall group were classified into anterolateral (22 cases), lateral (26 cases) and posterolateral (33 cases) subgroups. Patients in the septal group were classified into anteroseptal (10 cases), midseptal (71 cases) and posteroseptal (7 cases) subgroups. We analyzed the electrocardiographic features of these patients and in 87 patients with PVCs/VT originating from right ventricular outflow tract. Results: (1) A positive R wave inⅠ, aVL, V(5)-V(6) leads were found among most of patients, only few cases originating from tricuspid annulus anteroseptum group and tricuspid annulus anterolateral group demonstrated qr or qs pattern in aVL lead. 97.53% (79/81) patients demonstrated rS pattern in V(1)-V(3) leads with VAs originating from tricuspid annulus free wall, and 9/10 patients demonstrated rS pattern in V(1) lead with VAs originating from anteroseptum, and 97.44% (76/78) patients demonstrated QS pattern in V(1) lead with VAs originating from midseptum and posteroseptum. Precordial lead transition zone was on or behind V(3) for tricuspid annulus free wall group (96.3%, 78/81), but in front of V(3) for tricuspid annulus septum wall group (47.73%, 42/88) (P<0.01). The S wave's amplitude smaller than-1.81 mV in lead V(2) can be used as a cutoff value to identify if PVC/VT is originating from free wall or septum of TA. R wave in inferior wall leads was found among 98.85% (86/87) patients with PVCs/VT originating from right ventricular outflow tract. Conclusion: A positive R wave in Ⅰ, aVL, V(5)-V(6) leads was found among most of patients with idiopathic ventricular arrhythmias originating from the tricuspid annulus regions, but VAs originating from different portions of tricuspid annulus area have distinct electrocardiographic characteristics.

[Analysis of corneal and conjunctival sensitivities and its related factors of premature babies]

Objective: To analyse the corneal and conjunctival sensitivities of premature babies and to study the relevant influencing factors. Methods: Cross-sectional study. One hundred premature infants born at Women's Hospital School of Medicine Zhejiang University between May 2015 and September 2015 were enrolled, among which 51 were male (51%) and 49 were female (49%), the mean gestational age was (30.93±1.75)w, the mean corrected gestational age was (33.65±1.53)w, the mean birth weight was (1 592±336)g. The thresholds of cornea and conjunctiva of infants' left or right eyes were measured with Cochet-Bonnet aesthesiometer at 8-10 o'clock every morning when they naturally woke up, the minimum length of nylon wire that induced three successive times of eye-blink responses was recorded. Paired sample t test was used to compare the corneal and conjunctival sensitivities, the ocular surface sensitivities of preterm infants of different gender were compared using independent samples t-test, Pearson correlation and multiple linear regression analysis was conducted to analyze the correlation of corneal and conjuncitval sensitivities with gestational age, birth weight, age and corrected gestational age. Results: The mean corneal sensitivity was (44.85±5.53) mm and the mean conjunctival sensitivity was (23.50±5.48)mm in premature babies, corneal sensitivity was significantly higher than conjunctival sensitivity (t=25.620, P<0.001). No statistical significance was found between male and female preterm infants in corneal sensitivity [(44.80±5.83) mm vs. (44.90±5.25) mm, t=-0.085, P=0.933] and conjunctival sensitivity[(23.14±5.83) mm vs. (23.88±5.13) mm, t=-0.673, P=0.502]. Pearson correlation analysis showed that corneal sensitivity was significantly associated with conjunctival sensitivity in prematurity(r=0.676, P<0.001). There was significant correlation between corneal sensitivity and age, corrected gestational age (r=0.238, P=0.017; r=0.679, P<0.001), however no significant correlation was found between corneal sensitivity and gestational age, birth weight in preterm infants (r=0.067, P=0.510; r=-0.179, P=0.075). There was significant correlation between conjunctival sensitivity and corrected gestational age (r=0.490, P<0.001), however no significant correlation was found between conjunctival sensitivity and gestational age, birth weight and age in preterm infants (r=0.078, P=0.439; r=-0.096, P=0.344; r=0.151, P=0.133). Multiple linear regression revealed that corneal sensitivity(Y1) was positively correlated with corrected gestational age(X), the regression equation was Y1=2.45X-37.52, the conjunctical sensitivity(Y2) was also positively correlated with corrected gestational age(X), the regression equation was Y2=1.75X-35.41. Conclusions: The corneal sensitivity is higher than conjunctival sensitivity in premature babies.No statistical significance is found between male and female preterm infants in corneal sensitivity and conjunctival sensitivity. The corneal sensitivity and conjunctival sensitivity are correlated with corrected gestational age in preterm infants. The corneal and conjunctival sensitivities of premature babies tend to increase along with the increase of corrected gestational age. (Chin J Ophthalmol, 2018, 54: 115-119).

[A cross-sectional study on dyslipidemia in migrants in Inner Mongolia Autonomous Region]

Objective: To investigate the prevalence of dyslipidemia in migrants in Inner Mongolia Autonomous Region. Methods: A stratified multi-stage cluster equal size sampling was performed among the migrants aged ≥18 years who were engaged in manufacturing, wholesale retail, accommodation and catering service, social service, construction and other and 1 501 migrants from five area in Inner Mongolia Autonomous Region was investigated by means of questionnaires survey, physical measurements and laboratory detection. Results: Complete data was obtained in 1 496 study subjects. The prevalence of dyslipidemia was 42.65% (638/1 496), the age-standardized prevalence was 42.05%; the prevalence of hypercholesterolemia, hypertriglyceridemia, combined hyperlipidemia and low high-density lipoprotein hyperlipidemia were 4.90% (73/1 491), 14.76% (220/1 491), 4.83% (72/1 496), 25.27% (378/1 496), respectively. Dyslipidemia characterized by high triglyceride (HTG) and low high-density lipoprotein cholesterol (LHDL-C) accounted for 81.97% (523/638). The prevalence of dyslipidemia and HTG/LHDL-C dyslipidemia were similar, which increased significantly with age in both females and males, but was significantly higher in males. The prevalence among migrants with other occupations was highest. The prevalence of HTG/LHDL-C dyslipidemia didn't significantly increase with the duration of migration. However, the prevalence of high TG and dyslipidemia increased significantly with the duration of migration, the prevalence of high TG in age group <45 years showed the same characteristics. Conclusions: The prevalence of dyslipidemia in migrants in Inner Mongolia was high, and the main form was HTG/LHDL-C dyslipidemia. The prevalence in males, the middle aged and aged as well as those with other occupations were high. Migrants with longer duration of migration had higher prevalence of dyslipidemia.

Notch fatigue behavior: Metallic glass versus ultra-high strength steel

Studying the effect of notch on the fatigue behavior of structural materials is of significance for the reliability and safety designing of engineering structural components. In this work, we conducted notch fatigue experiments of two high-strength materials, i.e. a Ti_32.8Zr_30.2Ni_5.3Cu₉Be_22.7 metallic glass (MG) and a 00Ni18Co15Mo8Ti ultra-high strength steel (CM400 UHSS), and compared their notch fatigue behavior. Experimental results showed that although both the strength and plasticity of the MG were much lower than those of the UHSS, the fatigue endurance limit of the notched MG approached to that of the notched UHSS, and the fatigue ratio of the notched MG was even higher. This interesting finding can be attributed to the unique shear banding mechanism of MG. It was found that during fatigue process abundant shear bands formed ahead of the notch root and in the vicinity of the crack in the notched MG, while limited plastic deformation was observed in the notched UHSS. The present results may improve the understanding on the fatigue mechanisms of high-strength materials and offer new strategies for structural design and engineering application of MG components with geometrical discontinuities.

Effects of asymmetric nanostructures on the extinction difference properties of actin biomolecules and filaments

In this paper, symmetric and asymmetric tapering on the arms of the gammadion nanostructure is proposed to enhance both local field distribution and extinction difference (ED). The asymmetric tapered gammadion with tapering fraction (TF) of 0.67 is seen to have the largest ED and spatial local field distribution, producing a large wavelength shift of more than 50 percent as compared to the untapered gammadion nanostructures when immersed in a solution of actin molecules and filaments. The optical chirality, ζ shows that the larger local field amplitudes produced by the asymmetric designs increases the rate of chiral molecules excitation. This enhanced field is strongly rotating and highly sensitive to single molecules and larger filaments. Here, we show that the ED, optical chirality, sensitivity and rate of chiral molecules excitation can be improved by incorporating asymmetric designs into chiral gammadion nanostructures through tapering.

Celecoxib inhibits cell growth and modulates the expression of matrix metalloproteinases in human osteosarcoma MG-63 cell line

OBJECTIVE

The goal of this study was to determine the effect of celecoxib, a selective COX-2 inhibitor, on the growth inhibition of osteosarcoma and its potential anticancer mechanisms.

MATERIALS AND METHODS

Human osteosarcoma cell line MG-63 was used as a model. The inhibitory effect of celecoxib on cell proliferation was assessed by MTT assay. Flow cytometric analysis was used to detect the effects of celecoxib on cell cycle and apoptosis. Western blot analysis was used to detect the protein expression of RECK, matrix metalloproteinase (MMP)-2 and MMP-9 in celecoxib-treated MG-63 cells.

RESULTS

MTT assays showed that at a range of concentrations (0-80 µg/ml), celecoxib significantly inhibited the MG-63 cell proliferation in a time- and concentration-dependent manner. The half maximal inhibitory concentration (IC50) of celecoxib was 47.5 µg/ml for 24 h-treatment and 19.2 µg/ml for 48 h-treatment. Flow cytometric analysis demonstrated that treatment with 20 µg/ml celecoxib led to a significant cell cycle arrest at S-phase and an enhancement of apoptosis induction in MG-63 cells at 24 or 48h. Moreover, compared with 24 h-treatment, 48 h-treatment induced more S-phase arrest and apoptosis in MG-63 cells. Western blot analyses revealed that the expression of MMP-2 and MMP-9 was markedly down-regulated but RECK, an inhibitor of MMPs, was markedly up-regulated in MG-63 cells exposed to 20 µg/ml celecoxib for 24 or 48h. Furthermore, the effects of celecoxib on the expression of these molecules were more evident with the increase of treatment time.

CONCLUSIONS

Celecoxib inhibits the MG-63 cells proliferation through S-phase arrest and apoptosis induction. Celecoxib-induced down-regulation of MMP-2 and MMP-9 and up-regulation of RECK may contribute to the apoptosis induction and an alteration in local tumor microenvironment. These findings suggest that celecoxib may exert at least in part of its anticancer effects via up-regulation of RECK to inhibit the expression of MMP-2 and MMP-9.

Application of the paraboloidal model to assess mucosal changes following segmental intestinal transplantation in children

Segmental living related small intestinal transplantation (LRSITx) is a therapeutic option for conditions that present with short gut syndromes. Recovery of small intestinal mucosa after transplantation is critical to function. We examined the posttransplant mucosal changes to understand the absorptive capabilities of transplanted small intestine. The study of human subjects is constrained by limited biopsy material; therefore, we developed a technique of villus area measurement by extrapolation from two-dimensional surgical biopsy images. Using a detailed model of the villus as the gold standard, two simpler models (cylindrical and paraboloid) were tested. Comparisons with the accurate measurement revealed that the cylinder model does not compare well in early posttransplant biopsies. The paraboloid function developed in this article worked very well under all conditions. The simplicity of the paraboloid model and its robustness made high-quality estimates of the absorptive surface area from abundant data relatively easy. The remodeling expected in the initial stages of growth was also captured by this model. Time-dependent villus growth curves were obtained for transplanted bowel. Serial biopsies showed an initial "reconstruction" dip around 2 weeks after transplant, followed by continuous growth of villus surface area. An eventual plateau resulted at an average of 6 months after transplant. This growth of villi was shown to parallel the improved absorption of electrolytes, amino acids, and water.

Mesenchymal stem cell as salvage treatment for refractory chronic GVHD

Refractory chronic GVHD (cGVHD) is an important complication after allogeneic hematopoietic SCT and is prognostic of poor outcome. MSCs are involved in tissue repair and modulating immune responses in vitro and in vivo. From April 2005 to October 2008, 19 patients with refractory cGVHD were treated with MSCs derived from the BM of volunteers. The median dose of MSCs was 0.6 × 10(6) cells per kg body weight. Fourteen of 19 patients (73.7%) responded well to MSCs, achieving a CR (n=4) or a PR (n=10). The immunosuppressive agent could be tapered to less than 50% of the starting dose in 5 of 14 surviving patients, and five patients could discontinue immunosuppressive agents. The median duration between MSC administration and immunosuppressive therapy discontinuation was 324 days (range, 200-550 days). No patients experienced adverse events during or immediately after MSC infusion. The 2-year survival rate was 77.7% in this study. Clinical improvement was accompanied by the increasing ratio of CD5+CD19+/CD5-CD19+ B cells and CD8+CD28-/CD8+CD28+ T cells. In conclusion, transfusion of MSCs expanded in vitro, irrespective of the donor, might be a safe and effective salvage therapy for patients with steroid-resistant, cGVHD.

Bacillus circulans WZ-12—a newly discovered aerobic dichloromethane-degrading methylotrophic bacterium

A novel dichloromethane (DCM)-degrading bacterial strain named WZ-12 (GenBank accession no. EF100968) was isolated and identified as Bacillus circulans based on standard morphological and physiological properties and nucleotide sequence analysis of enzymatically amplified 16S ribosomal deoxyribonucleic acid. DCM dehalogenase from B. circulans WZ-12 was purified to 8.27-fold with a yield of 34.83%. The electrophoretically homogeneous-purified enzyme exhibited a specific activity of 118.82 U/mg. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified DCM dehalogenase gave a distinct band with an estimated molecular mass of 20,000 +/- 1,000.

Antioxidant activities of cultured Armillariella mellea

This study aimed to evaluate the antioxidant activities of a cultured medicinal fungus--Armillariella mellea (Vahl. ex Fr.) Karst. (AM). Three antioxidant assay systems, namely cytochrome c, xanthine oxidase inhibition and FeCl2-ascorbic acid stimulated lipid peroxidation in rat tissue homogenate tests, were used. Total flavonoid and phenol contents of AM extracts were also analyzed. Results showed that both aqueous (AM-H2O) and ethanolic (AM-EtOH) extracts of solid state cultured AM showed antioxidant activities in a concentration-dependent manner. At concentrations 1-100 microg/ml, the free radical scavenging activity was 73.7-92.1% for AM-H2O, and 60.0-90.8% for AM-EtOH. These extracts also showed an inhibitory effect on xanthine oxidase activity, but with a lesser potency (IC50 - 9.17 microg/ml for AM-H2O and 7.48 microg/ml for AM-EtOH). In general, AM-H2O showed a stronger anti-lipid peroxidation activity on different rat's tissues than AM-EtOH. However, both AM extracts displayed a weak inhibitory effect on lipid peroxidation in plasma. Interestingly, the anti-lipid peroxidation activity of AM-H2O (IC50 - 6.66 microg/ml) in brain homogenate was as good as alpha-tocopherol (IC50 - 5.42 microg/ml). AM-H2O (80.0 mg/g) possessed a significant higher concentration of total flavonoids than AM-EtOH (30.0 mg/g), whereas no difference was noted in the total phenol content between these two extracts. These results conclude that AM extracts possess potent free radical scavenging and anti-lipid peroxidation activities, especially the AM-H20 in the brain homogenate.

Computer-aided diagnosis system for acute stroke using diffusion weighted images with volume calculation

The diffusion weighted image (DWI) technique is routinely used for diagnosis and treatment of early stroke due to its superior performance, especially when it is compared with conventional magnetic resonance image (MRI) for detection of acute ischemic stroke. Using DWI examination, This work has proposed a computer-aided diagnosis system, which can effectively calculate the volume size of a lesion and provide clinical doctor the 3D reconstruction data of the lesion. The potential benefits of using our system include the higher accuracy of acute stroke lesion definition, the reduced time and procedure of calculating the volume of a lesion, and providing 3D reconstruction image of stroke patients, which can effectively assist doctors in making more accurate diagnoses and treating patients in a more convenient way. Compared with the traditional method, the experimental results have shown the superior performance of this proposed system.

Supercritical carbon dioxide extract exhibits enhanced antioxidant and anti-inflammatory activities of Physalis peruviana

Physalis peruviana L. (PP) is a medicinal herb widely used in folk medicine. In this study, supercritical carbon dioxide (SFE-CO2) method was employed to obtain three different PP extracts, namely SCEPP-0, SCEPP-4 and SCEPP-5. The total flavonoid and phenol concentrations, as well as antioxidant and anti-inflammatory activities of these extracts were analyzed and compared with aqueous and ethanolic PP extracts. Among all the extracts tested, SCEPP-5 demonstrated the highest total flavonoid (234.63+/-9.61 mg/g) and phenol (90.80+/-2.21 mg/g) contents. At concentrations 0.1-30 microg/ml, SCEPP-5 also demonstrated the strongest superoxide anion scavenging activity and xanthine oxidase inhibitory effect. At 30 microg/ml, SCEPP-5 significantly prevented lipopolysaccharide (LPS; 1 microg/ml)-induced cell cytotoxicity in murine macrophage (Raw 264.7) cells. At 10-50 microg/ml, it also significantly inhibited LPS-induced NO release and PGE2 formation in a dose-dependent pattern. SCEPP-5 at 30 microg/ml remarkably blocked the LPS induction of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression. Taken together, these results suggest that SCEPP-5, an extract of SFE-CO2, displayed the strongest antioxidant and anti-inflammatory activities as compared to other extracts. Its protection against LPS-induced inflammation could be through the inhibition of iNOS and COX-2 expression.

Molecular cloning and structural analysis of the gene encoding Bacillus cereus exochitinase Chi36

The chi36 gene encoding exochitinase Chi36 was cloned from a Bacillus cereus 6E1 subgenomic library. The chi36 open reading frame is 1080 bp long encoding a Chi36 precursor protein of 360 amino acids, consisting of a 27 amino acid N-terminal signal peptide and a 333 amino acid sequence found in the mature Chi36 protein of 36.346 kDa. Chi36 shows significant amino acid sequence similarity to many bacterial chitinases, but has highest similarity to B. circulans WL-12 chitinase D. Chi36 belongs to subfamily B of bacterial chitinases in family 18 of glycosyl hydrolases. Chi36 shows a simple and compact structural organization composed of an N-terminal signal peptide and a C-terminal (beta/alpha)8-barrel catalytic domain (CaD). The Chi36 signal peptide is recognized by Escherichia coli, allowing Chi36 secretion. Chi36 is the first one-domain (CaD) bacterial chitinase cloned from B. cereus.

Investigation of the microstructure and mesotexture formed during thermomechanical controlled rolling in microalloyed steels

Thermomechanical controlled rolling (TMCR) has been widely used as an effective method to improve the properties of steels. In the present paper, two commercial TMCR microalloyed steels were investigated. The grain size distributions and grain boundary misorientation angles were measured using electron backscattered diffraction patterns obtained using orientation imaging microscopy (OIM). The equivalent grain diameters were also measured using optical microscopy. Mixed coarse- and fine-grained regions were observed and the microhardness values were measured for both areas. Grain boundary misorientation angle distributions showed that the magnitude of mesotexture developed in the steel is dependent upon the rolling passes, the reduction ratio and the rolling temperatures including the finish rolling temperature. The surface layer, up to 2 mm depth, in Com-A steel had about 55% of grain boundaries with a misorientation angle below 12 degrees, much higher than in the central area ( approximately 30%), whereas Com-B steel showed similar distributions from the rolling surface to the centre. Misorientation results obtained from laboratory rolled steel plates with various TMCR procedures are also discussed as are OIM results from Charpy impact brittle fracture surfaces examining the effect of misorientation on crack propagation.

Human dendritic cells as targets of dengue virus infection

Dengue virus infections are an emerging global threat. Severe dengue infection is manifested as dengue hemorrhagic fever and dengue shock syndrome, both of which can be fatal complications. Factors predisposing to complicated disease and pathogenesis of severe infections are discussed. Using immunohistochemistry, immunofluorescence, flow cytometry, and ELISA techniques, we studied the cellular targets of dengue virus infection, at both the clinical (in vivo) and the laboratory (in vitro) level. Resident skin dendritic cells are targets of dengue virus infection as demonstrated in a skin biopsy from a dengue vaccine recipient. We show that factors influencing infection of monocytes/macrophages and dendritic cells are different. Immature dendritic cells were found to be the cells most permissive for dengue infection and maybe early targets for infection. Immature dendritic cells exposed to dengue virus produce TNF-alpha protein. Some of these immature dendritic cells undergo TNF-alpha mediated maturation as a consequence of exposure to the dengue virus.

Localization and characterization of acharan sulfate in the body of the giant African snail Achatina fulica

Acharan sulfate is a glycosaminoglycan (GAG), having the structure -->4)-2-acetamido-2-deoxy-alpha-D-glucopyranose(1-->4)-2-sulfo-alpha-L-idopyranosyluronic acid (1-->, isolated from the body of the giant African snail Achatina fulica. This GAG represents 3-5% of the dry weight of this snail's soft body tissues. Frozen sections and polyester wax sections of the snail's body were stained by Alcian blue-periodic acid-Schiff's reagent (PAS) to localize acharan sulfate. Alcian blue staining indicated that GAG was mainly secreted into the outer surface of the body from internal granules. A highly mucous material was collected and treated and the acharan sulfate was recovered by ethanol and cetyl pyridinium chloride precipitation. Crude acharan sulfate was purified by DEAE-Sephacel ion-exchange chromatography. Depolymerization of intact mucus and purified acharan sulfate fractions by heparin lyase II (heparitinase I) from Flavobacterium heparinum produced an unsaturated disaccharide as a major product, establishing the repeating unit of acharan sulfate. These results demonstrate that mucus in the granule and secreted to the outside of the body is composed entirely of acharan sulfate.

Tetrahydrobiopterin-deficient hyperphenylalaninemia in the Chinese

BACKGROUND

Hyperphenylalaninemia (HPA) may be caused by either a deficiency in phenylalanine-4-hydroxylase or in tetrahydrobiopterin (BH4), the essential cofactor required for the hydroxylation of aromatic amino acids. The most common forms of BH4 deficiency are 6-pyruvoyl-tetrahydropterin synthase (PTPS) deficiency (MIM 261640) and dihydropteridine reductase (DHPR) deficiency (MIM 261630), which require a different treatment from classical HPA.

RESULTS

Approximately 86% of BH4-deficient HPA in the Chinese population was found to be caused by PTPS deficiency. Eleven missense (73C-->G, 120T-->G, 155A-->G, 166G-->A, 200C-->T, 209T-->A, 226C-->T, 259C-->T, 286G-->A, 317C-->T, 430G-->C), one splicing (IVS3+1G-->A) and two deletion mutations (116-119delTGTT, 169-171delGTG) were identified in 37 unrelated PTPS-deficient Chinese families. Among these, 155A-->G, 259C-->T and 286G-->A mutation accounted for about 80% of the mutant alleles. The 155A-->G and 286G-->A mutations were found to be the common mutation in southern and northern Chinese, respectively. Only two Chinese DHPR-deficient families were detected among about 300 Chinese hyperphenylalaninemia cases. A single base transition 508G-->A on the DHPR cDNA was identified in two consanguineous DHPR-deficient siblings. A reduced level of DHPR mRNA expression was found in the other DHPR-deficient patient, which suggested that the mutation might lie in the regulatory region of the DHPR gene.

CONCLUSIONS

The BH4-deficient HPA was estimated to make up around 30% of the Chinese population in Taiwan suffering from HPA, which is much higher than in Caucasian populations (1.5-2% of HPA).

Development and evaluation of serotype- and group-specific fluorogenic reverse transcriptase PCR (TaqMan) assays for dengue virus

Five fluorogenic probe hydrolysis (TaqMan) reverse transcriptase PCR (RT-PCR) assays were developed for serotypes 1 to 4 and group-specific detection of dengue virus. Serotype- and group-specific oligonucleotide primers and fluorogenic probes were designed against conserved regions of the dengue virus genome. The RT-PCR assay is a rapid single-tube method consisting of a 30-min RT step linked to a 45-cycle PCR at 95 and 60 degrees C that generates a fluorogenic signal in positive samples. Assays were initially evaluated against cell culture-derived dengue stock viruses and then with 67 dengue viremic human sera received from Peru, Indonesia, and Taiwan. The TaqMan assays were compared to virus isolation using C6/36 cells followed by an immunofluorescence assay using serotype-specific monoclonal antibodies. Viral titers in sera were determined by plaque assay in Vero cells. The serotype-specific TaqMan RT-PCR assay detected 62 of 67 confirmed dengue virus-positive samples, for a sensitivity of 92.5%, while the group-specific assay detected 66 of 67 confirmed dengue virus-positive samples, for a sensitivity of 98.5%. The TaqMan RT-PCR assays have a specificity of 100% based on the serotype concordance of all assays compared to cell culture isolation and negative results obtained when 21 normal human sera and plasma samples were tested. Our results demonstrate that the dengue virus TaqMan RT-PCR assays may be utilized as rapid, sensitive, and specific screening and serotyping tools for epidemiological studies of dengue virus infections.

Different combinations of the heat-shock cognate protein 70 (hsc70) C-terminal functional groups are utilized to interact with distinct tetratricopeptide repeat-containing proteins

A group of tetratricopeptide repeat (TPR)-containing proteins has been shown to interact with the C-terminal domain of the 70 kDa heat-shock cognate protein (hsc70). In the present study, the effect of the TPR-containing proteins, including the C-terminus of hsc70-interacting protein (CHIP), TPR1 and human glutamine-rich TPR-containing protein (hSGT), on refolding of luciferase by DnaJ and hsc70 was investigated. These proteins inhibited the restoration of luciferase activity by the chaperones. The inhibitory effect exerted by TPR1 and hSGT depended upon their binding to hsc70. However, the interaction with hsc70 did not appear to be required for the inhibition of luciferase refolding by CHIP. We also demonstrate that the peptide, GPTIEEVD, corresponding to the C-terminal end of hsc70, abolished the association of [(3)H]hsc70 with CHIP, TPR1 and hSGT. This implied that the GPTIEEVD motif of hsc70 was responsible for interacting with these TPR-containing proteins. However, the GGXP-repeats (where X is any aliphatic residue), another C-terminal conserved motif of vertebrate hsc70s, were not essential for interacting with the TPR-containing proteins. On the basis of mutagenesis studies, it was clear that a unique combination of the functional groups in the GPTIEEVD motif were utilized to interact with each TPR-containing protein, suggesting that inhibitors can be designed and used to elucidate the functional role of these interactions.

Detection of dengue viral RNA using a nucleic acid sequence-based amplification assay

Faster techniques are needed for the early diagnosis of dengue fever and dengue hemorrhagic fever during the acute viremic phase of infection. An isothermal nucleic acid sequence-based amplification (NASBA) assay was optimized to amplify viral RNA of all four dengue virus serotypes by a set of universal primers and to type the amplified products by serotype-specific capture probes. The NASBA assay involved the use of silica to extract viral nucleic acid, which was amplified without thermocycling. The amplified product was detected by a probe-hybridization method that utilized electrochemiluminescence. Using normal human plasma spiked with dengue viruses, the NASBA assay had a detection threshold of 1 to 10 PFU/ml. The sensitivity and specificity of the assay were determined by testing 67 dengue virus-positive and 21 dengue virus-negative human serum or plasma samples. The "gold standard" used for comparison and evaluation was the mosquito C6/36 cell culture assay followed by an immunofluorescent assay. Viral infectivity titers in test samples were also determined by a direct plaque assay in Vero cells. The NASBA assay was able to detect dengue viral RNA in the clinical samples at plaque titers below 25 PFU/ml (the detection limit of the plaque assay). Of the 67 samples found positive by the C6/36 assay, 66 were found positive by the NASBA assay, for a sensitivity of 98.5%. The NASBA assay had a specificity of 100% based on the negative test results for the 21 normal human serum or plasma samples. These results indicate that the NASBA assay is a promising assay for the early diagnosis of dengue infections.

Neonatal screening for glucose-6-phosphate dehydrogenase deficiency in Taiwan

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathic disease in Taiwan. The mass neonatal screening of G6PD deficiency by fluorometric spot test in Taiwan was started with a pilot program in 1984. The nationwide screening was started on July 1, 1987, and a follow-up system comprising of eighteen referral hospitals, including outlying islands, was organized for confirmatory test, medical care and genetic counseling. From July 1987 to December 1997, 2,971,192 heel blood samples collected on filter paper from 1,143 delivery units were screened by four neonatal screening centers. 46,570 cases were confirmed as G6PD deficiency is estimated to be around 2.1% (male 3.1%, female 0.9%) in Taiwan. The coverage rate of neonatal screening was 99% in 1997. To assess the reliability of the confirmatory test, an external quality assurance (QA) program for G6PD assay was developed. Periodically, 3 or 5 lyophilized quality control materials with different activities of G6PD were sent to each referral hospital by speed post delivery in dry ice. From January 1988 to June 1998, 85 QA services were performed. Two hundred and seven (13.5%) abnormal QA results were found, which were attributed to clerk (11.6%), procedural (16.4%), and instrumental errors (47.3%). In aid to confirm G6PD deficiency, a method to detect the G6PD mutation by using the dried blood samples was developed. The frequencies of the mutant alleles in Taiwan were determined to be 46.8% (1376G > T), 16.2% (1388G > A), 7.9% (95A > G), 6.5% (493A > G), 5.6% (392G >T), 4.6% (1024C > T), 0.5% (487G > A) and 0.5% (519C > G), respectively.

The effect of mutating arginine-469 on the substrate binding and refolding activities of 70-kDa heat shock cognate protein

On the basis of the X-ray structure of DnaK, we obtained an energy-minimized model for the C-terminal domain of rat 70-kDa heat shock cognate protein (hsc70). The model suggests that Arg-469 may play an important role in maintaining the substrate-bound conformation of hsc70. To verify this hypothesis, we substituted cysteine for Arg-469 and generated the hsc70(R469C) mutant. Compared to the wild-type hsc70, the mutant was more accessible to cleavage by endopeptidase Lys-C, implying that the overall structure of hsc70(R469C) is relatively loose. Moreover, hsc70(R469C) did not form tightly associated complexes with S-carboxymethyl-alpha-lactalbumin, an unfolded protein. The amount of heptapeptide FYQLALT bound to hsc70(R469C) was also decreased as determined by gel filtration. Thus, the affinity of hsc70(R469C) for polypeptide substrates is reduced. In the presence of DnaJ, the capability of hsc70(R469C) to refold the denatured luciferase was decreased by 50%. Therefore, for hsc70, reduction in affinity for substrates may affect its DnaJ-dependent refolding activity.

Ultrasound phased arrays for prostate treatment

The effect of array geometry on the steering performance of ultrasound phased arrays is examined theoretically, in order to maximize array performance under the given anatomical constraints. This paper evaluates the performance of arrays with spherical and cylindrical geometry, determined by using computer simulations of the pressure fields produced at various extremes of steering. The spherical segment arrays were truncated for insertion into the rectum, and contained either annular or linear elements. The cylindrical arrays were either flat or had a variable curvature applied along their length. Fields were computed by dividing the array elements into many point sources. The effectiveness of an array configuration when steered to a particular focal location was assessed by defining a parameter, G, as the ratio of the intensity at the desired focus to the maximum intensity of any unwanted lobes. The performance of truncated spherical arrays with annular elements was evaluated for focal steering along the array axis (in depth, in the z direction). When steered 15 mm toward the source, these truncated spherical annular arrays exhibited excellent performance, with G>5.7 for arrays containing more than 10 elements. Similarly, the spherical arrays with linear elements performed well when steered along the array axis to the same degree, with G>7 (for element widths up to 3 lambda), though many more array elements were required. However, when these arrays were steered 15 mm laterally, along the length of the prostate (the y direction), the value for G fell below 1 for element widths greater than about 1.6 lambda. It was found that the cylindrical arrays performed much better for y-direction steering (G>4, for 60 mm arrays with an element width of 1.75 lambda), but their performance was poorer when steered in the z direction (G approximately 4 for an element width of 1.5 lambda). In order to find a compromise between these extremes, a curved cylindrical array was examined, which was a cylindrical array with additional curvature along its length. These curved cylindrical arrays yielded performance between that of spherical linear arrays and cylindrical arrays, with better steering along the y direction than the spherical arrays and better z-direction steering than the cylindrical arrays.

Evaluation of hepatoprotective activity of legumes

Mung bean, adzuki bean, black bean and rice bean are foods and folk medicines of Taiwan. We evaluated the effects of various water extract concentrations (100, 500 and 1000 mg/kg body wt.) and silymarin (25 mg/kg body wt. on acetaminophen-induced liver injury by measuring serum glutamate-oxalate-transaminase (sGOT) and serum glutamate-pyruvate-transaminase (sGPT) activities in rats. The results showed that the sGOT and the sGPT activities, increased by APAP, were decreased significantly (P < 0.05) through treatment with inceasing amounts up to 1000 mg/kg body wt. of the exracts. In particular, the mung bean aqueous extract showed the best hepatoprotective effect on APAP-induced hepatotoxicity. The pathological changes of liver injury caused by APAP improved by the treatment with all of the legume extracts, which were compared to silymarin as a standardized drug. In addition to these results, the extract of mung bean acted as a potential hepatoprotective agent in dietary supply.

[A measure of chronic respiratory disease questionnaire for clinical trail]

OBJECTIVE

The aim of this paper was to investigate the reliability and validity of the Chronic respiratory disease questionnaire (CRQ) in China.

METHOD

Sixty-eight patients with chronic respiratory disease who were in hospital from January to November, 1999 were surveyed with CRQ. Eighteen patients were investigated repeatedly with CRQ in one week to test the reliability; before and the 10th day after treatment, 50 patients were surveyed twice with CRQ and the peakflow of these patients were also detected. The same doctor explained questionnaires and tested peakflow.

RESULTS

The correlated analysis of reliability was positive (r = 0.732, P < 0.01). The correlated analysis between the difference of twice-questionnaire scores and the difference of twice-peakflow value was also positive (r = 0.565, P < 0.01).

CONCLUSION

CRQ can be used by the clinical doctors of China.

Neutralizing monoclonal antibodies can potentiate IL-5 signaling

IL-5 is a major determinant in the survival, differentiation and effector-functions of eosinophils. It mediates its effect upon binding and activation of a membrane bound receptor (R), composed of a ligand-specific alpha-chain and a beta-chain, shared with the receptors for IL-3 and granulocyte-macrophage colony-stimulating factor. We have generated and mapped the epitopes of three monoclonal antibodies (mAb) directed against this cytokine: the strong neutralizing mAb 5A5 and 1E1, and the very weak neutralizing mAb H30. We found that H30 as well as 5A5 can increase proliferation above the level induced by human (h)IL-5 alone, in a JAK-2-dependent manner, and at every sub-optimal hIL-5 concentration analyzed. This effect is dependent on mAb-mediated cross-linking of IL-5R complexes, and is only observed on cell lines expressing a hybrid human/mouse IL-5Ralpha-chain. We discuss these findings in view of the stoichiometric and topological requirements for an activated IL-5R. Since humanized anti-IL-5 mAb are currently in clinical testing, our findings imply that such mAb should be carefully evaluated for their potentiating effects.

Valveless outflow reconstruction using autologous tissue as a posterior wall for pulmonary atresia with ventricular septal defect

BACKGROUND AND PURPOSE

Reoperation is inevitable for some patients with pulmonary atresia who receive a heterograft or homograft in a primary Rastelli operation. Nonetheless, the need for reoperation in patients with classic Fallot's tetralogy who have undergone total correction with a transannular patch is unusual. We sought to change pulmonary atresia into Fallot's tetralogy and used a transannular patch instead of the conventional Rastelli operation.

PATIENTS AND METHODS

Valveless outflow direct reconstruction was performed on 10 consecutive patients with pulmonary atresia and ventricular septal defect between August 1997 and 1999. Patient ages ranged from 1.3 to 11.5 years. A Blalock-Taussig shunt was previously constructed in four of these patients and a central shunt was constructed in five. The major aortopulmonary collateral arteries were occluded in one patient by repeated coil embolization after the central shunt. The strategy was to connect the right ventriculotomy with the pulmonary arteries directly, even if there was a gap with a long atretic cord. In patients with a previous central shunt covered with a Gore-Tex membrane, the reactive visceral pericardium over the in situ tissue (the left atrium, right ventricle, or aorta) was used as the autologous posterior wall. Thus, only autologous, fresh pericardium without a valve was used to cover the anterior part of the right ventricular outflow tract, as in the repair of classic Fallot's tetralogy with a transannular patch.

RESULTS

There was no mortality, and the postoperative central venous pressure was low in all patients. No gradient was noted across the right ventricular outflow tract. Follow-up echocardiography revealed a competent tricuspid valve with mild pulmonary regurgitation in all patients.

CONCLUSIONS

The results of this study suggest that valveless outflow direct reconstruction provides adequate pulmonary circulation without hypertension in pulmonary atresia patients with a ventricular septal defect if the tricuspid valve is competent.

A minimal transverse incision with low median sternotomy for pediatric congenital heart surgery

OBJECTIVES

Median sternotomy is the incision of choice for most cardiac surgical procedures, but the full-length vertical skin incision generally leaves an unsightly scar. In certain patients undergoing short, low-risk procedures, cosmetic considerations are of relatively greater importance.

METHODS

A minimal transverse curvilinear skin incision with low median sternotomy is described which gives adequate exposure for selected open-heart procedures. Since September 1997, this approach has been used in 22 pediatric patients undergoing open-heart surgery including five cases of Fallot's tetralogy. We also compared the operation time and result with other approaches.

RESULTS

Using this modified method, the exposure of the heart was good enough, and there were no difficulties in cannulating the ascending aorta for cardiopulmonary bypass. Although it took a longer time to close the wound, the operation time was similar to the standard approach. The small transverse wound was not visible under conventional clothes.

CONCLUSIONS

A minimal transverse incision with low median sternotomy provides an alternative approach for small wound open-heart surgery in patients with a simple congenital cardiac defect. It is technically feasible and has a good cosmetic result.

Modified arterial switch operation by sharing the common wall between the great arteries

BACKGROUND

Suprapulmonary stenosis and coronary arterial obstruction still remain as problems after an arterial switch operation (ASO). We used a modified ASO applying the common wall and in situ transfer techniques to improve the current procedure.

METHODS

From October 1996 to December 1997, 11 babies aged 6 days to 3 months with transposition of the great arteries underwent a modified ASO which included sharing the common wall between the great arteries until above the anterior neoaortic suture-line for coronary and pulmonary artery reconstruction. Coronary arteries were of usual type in three cases, juxtacommissural origin in five, and a high takeoff in one; all were redirected almost in situ.

RESULTS

There was no early death (< 30 d), coronary or bleeding problems. One late death occurred after a repeat surgery for suprapulmonary stenosis. This was caused by upward stretching of the left pulmonary artery, which was placed above the high left-sided neoaortic anastomosis for in situ transfer of the high takeoff coronary arteries. Intraluminal growth of the adventitia also contributed to suprapulmonary stenosis, which decreased significantly when the common wall adventitia was cleaned in the last two cases we operated on. Ten patients were doing well at follow-up (30.9 +/- 5.2 mo).

CONCLUSIONS

This modified ASO by common wall and in situ transfer might avoid coronary kinking and lessen the chance of postoperative bleeding. To avoid suprapulmonary stenosis, common wall adventitia inside the pulmonary pathway should be cleaned, and the left and right pulmonary arteries should also be kept in situ as possible as in coronary redirection.

Combined atrial and arterial switch operations for congenitally corrected transposition

Conventional repair of congenitally corrected transposition of the great arteries (CCTGA) is directed at eliminating the associated defects and leaves the right ventricle in a systemic position. The long-term outcome of this procedure may involve deterioration of right ventricular function with tricuspid regurgitation and failure of the conduction system. We describe two consecutive patients with CCTGA, one of whom had apicocaval juxtaposition. The patients were aged 19 and 16 months, respectively, and both underwent a combination of atrial and arterial switch. These are the first two reported cases of successful completion of this type of operation in Taiwan. Our review of previously reported cases suggested that no significant difference exists in the outcome of patients with this condition who undergo either arterial switch or Rastelli-type repair plus atrial redirection. However, reported patients who underwent anatomic repair had lower early mortality, late mortality, and incidence of complete heart block than those who underwent conventional repair. The present two cases and our review of the literature suggest that, among patients with apicocaval juxtaposition, 1) Mustard operation is optimal for patients with small atrial volume; 2) one-and-one-half ventricular repair may be helpful to the outcome, especially when treatment is combined with Rastelli-type repair; and 3) excellent access to the ventricular septal defect through the tricuspid valve is afforded via a left atriotomy. From the present two cases and our review of the literature, we conclude that anatomic repair is superior to conventional repair of CCTGA in terms of protection against dysfunction and failure of the anatomic right ventricle, tricuspid valve, and conduction system. Long-term follow-up is mandatory.

Multisite mutagenesis of interleukin 5 differentiates sites for receptor recognition and receptor activation

Multisite mutagenesis of single-chain and monomeric forms of human interleukin 5 (IL-5) was performed to investigate mechanistic features of receptor activation and the possibility of differentiating sites of activation from those for receptor interaction. The normally dimeric human IL-5 contains two domains, each containing a four-helix bundle. IL-5 has previously been re-engineered into the monomeric, one-domain GM1 form by introducing an eight-residue linker between the third and fourth helices. In this study, we tested a combination of mutations in a single-chain IL-5 (scIL-5) construct, [(89)SLRGG(92),W(110)/(89)AAAAA(92), A(110)]scIL-5. This mutein was found to retain substantial IL-5 receptor alpha-chain binding but with selectively suppressed proliferation of the IL-5-dependent cell line TF-1.28. This result confirms recent findings that IL-5 receptor alpha-chain recognition can be supported by the (89)SLRGG(92) epitope and that, in contrast, Glu110 is important in receptor activation. On the basis of this result, two mutants of GM1 were constructed with the intent to retain receptor alpha-chain binding while modifying receptor activation epitopes. In the first, [(88)SLRGG(92),W(110)]GM1, the wild-type CD-loop sequence (89)EERRR(92) was converted to the mimotope (89)SLRGG(92), and Glu110 to Trp. In the second, [A(13), A(110)]GM1, wild-type Glu13, and Glu110 were both mutated to Ala. GM1 and mutants were expressed in high yield in Escherichia coli, purified under denaturing conditions from inclusion bodies, and refolded. Monomers were screened for binding to shIL-5Ralpha-Fc using optical biosensor and ELISA and for bioactivity by proliferation of TF-1.28 cells. Both [(88)SLRGG(92),W(110)]GM1 and [A(13),A(110)]GM1 were found to interact with the shIL-5Ralpha-Fc, with affinities of 69-585 nM, 2-15-fold weaker than that of the original GM1. The mutants also were able to compete with IL-5 for binding to shIL-5Ralpha in an ELISA. In contrast, both mutants exhibited a disproportionately decreased capacity to stimulate TF-1. 28 cell proliferation. [A(13),A(110)]GM1 bioactivity was 160-fold lower than that of GM1, while that for the [(88)SLRGG(92),W(110)]GM1 mutant was 2600-fold lower. The largely retained IL-5 receptor alpha-chain binding affinities versus relatively suppressed bioactivities of [A(13),A(110)]GM1 and [(88)SLRGG(92),W(110)]GM1 variants, in particular the latter, point to the existence of separable IL-5 epitopes for receptor binding and activation and establish the potential to design smaller IL-5 mimetic antagonists.

Pulmonary venous obstruction in patients with transposition of the great arteries

We report two cases of complete transposition of the great arteries with pulmonary venous obstruction which was diagnosed by intraoperative transesophageal echocardiography, but was not detected by transthoracic echocardiography and cardiac catheterization. The pulmonary venous obstruction was relieved simultaneously with arterial switch operation. The intraoperative transesophageal echocardiography has great contribution for thorough evaluation of the pulmonary venous return of the patients.