Effects of a novel anti-exospore monoclonal antibody on microsporidialNosema bombycisgermination and reproductionin vitro

A monoclonal antibody (mAb) 3C2, against an exospore protein of the microsporidiumNosema bombycis(N. bombycis) was prepared, and its effects on microsporidial germination and reproductionin vitrowere studied. MAb 3C2 was effective in inhibiting the germination and subsequent infection ofBombyx moricells compared to the control mAb. The antigen was isolated by 2-dimensional gel electrophoresis. Immunoblotting revealed it to be an 84 kDa protein corresponding to pI (7·2) on the 2-D gel. The present results suggest that the antibodies can be used for diagnostic purposes and for developing new therapeutic strategies in controlling microsporidian diseases.

Introduction of Microsurgical Technique to Biliary Reconstruction in Living Donor Liver Transplantation

OBJECTIVE

High rates of biliary complications continue to be a major concern associated with living donor liver transplantation (LDLT). In this article, we report our experience of applying a microsurgical technique to biliary reconstruction in LDLT.

PATIENTS AND METHODS

From January 2001 to December 2005, 32 patients underwent LDLTs (8 children and 24 adults). Biliary reconstruction for 43 hepatic duct orifices in the 32 donor grafts 21 duct-to-duct anastomoses, and 22 cholangiojejunostomies. Nine cholangiojejunostomies in 4 donors used a microsurgical technique under an operative microscope.

RESULTS

Biliary complications weren't observed among the cases of cholangiojejunostomy using a microsurgical technique. An anastomotic biliary leakage was found in a recipient with cholangiojejunostomy performed using a surgical loupe and a biliary stricture in another recipient who underwent duct-to-duct anastomoses using a surgical loupe.

CONCLUSION

Introduction of a microsurgical technique for biliary reconstruction in LDLT, especially using an operating microscope in the setting of hepatico-jejunostomy for small hepatic duct (< or =2 mm in diameter), showed good results. We believe that using the operative microscope for biliary reconstruction could reduce the incidence of biliary complications associated with LDLT.

Unilateral low-frequency stimulation of central piriform cortex inhibits amygdaloid-kindled seizures in Sprague–Dawley rats

The central piriform cortex (cPC) is considered to be critically involved in the generation and propagation of kindled seizures. Our previous study found that low-frequency stimulation (LFS) of the cPC inhibits the development process of amygdala kindling. In this study, we determined whether unilateral LFS of the cPC had an inhibitory effect on amygdaloid-kindled seizures in Sprague-Dawley rats. When fully-kindled seizures were achieved by daily amygdala electrical stimulation (2 s train of 1 ms pulses at 60 Hz and 150-300 microA), LFS (15 min train of 0.1 ms pulses at 1 Hz and 50-150 microA) was applied to the ipsilateral or contralateral cPC 1 s after cessation of kindling stimulation for 10 days. LFS of the ipsilateral cPC significantly decreased the incidence of generalized seizures and seizure stage, and shortened cumulative afterdischarge duration and cumulative generalized seizure duration. LFS of the contralateral cPC also significantly decreased the expression of seizure stage, but had no appreciable effect on the generalized seizure incidence, cumulative afterdischarge duration and cumulative generalized seizure duration. On the other hand, LFS of the ipsilateral cPC significantly increased the afterdischarge threshold and further increased the differences of current intensity between afterdischarge threshold and generalized seizure threshold. Our data suggest that LFS of the cPC may be an effective method of inhibiting kindled seizures by preventing both afterdischarge generation and propagation. It provide further evidence that brain regions like the cPC, other than the seizure focus, can serve as targets for deep brain stimulation treatment of epilepsy.

Antisense ERK1/2 oligodeoxynucleotide gene therapy attenuates graft arteriosclerosis of aortic transplant in a rat model

Chronic rejection is a major cause of transplant loss that is effected by the extracellular signal-regulated kinases (ERK) pathway. This study investigated the effects of antisense ERK1/2 oligodeoxynucleotide(ODN) gene therapy on chronic rejection.

METHODS

Lewis (RT1(1)) rats served as recipients of Brown-Norway (BN, RT1n) grafts. The BN rat abdominal aortas were harvested and orthotopically grafted into Lewis rats. The recipients were divided into three groups: (1) control group (n = 9), (2) random ODN transfer group (n = 10), and (3) antisense ODN transfer group (n = 10). At day 60 after transplantation, the recipients were sacrificed; the grafted aortas were evaluated histologically and immunohistochemically. ERK1/2 protein expression in the grafts was determined using Western Blot assays. Serum levels of slCAM-1 were detected by ELISA.

RESULTS

In the control group and random ODN transfer group, we observed a remarkable degree of intimal hyperplasia and inflammatory cell infiltration, including macrophages and T cells. Compared with the control group, antisense ERK1/2 ODN gene therapy resulted in a significant reduction in neointimal proliferation (P < .01), inhibition of ERK1/2 protein expression (P < .01), decreased graft infiltration with CD4+ T lymphocytes (P < .01), CD8+ T lymphocytes(P < .05), and ED-1 macrophages (P < .01) with decreased serum levels of sICAM-1 (P < .05). We obtained a negative correlation between ERK1/2 expression and immune cell infiltration or ICAM-1 level.

CONCLUSIONS

Antisense ERK1/2 gene therapy can attenuate graft arteriosclerosis so as to protect aortic allografts. The protection seemed to correlate with inhibition of inflammatory infiltration, implying that the ERK1/2 signal transduction pathway plays an important role in the process of chronic vascular rejection.

A polymorphism in SOD2 is associated with development of Alzheimer's disease

Genes involved in cellular mechanisms to repair oxidative damage are strong candidates as etiologic factors for Alzheimer's disease (AD). One important enzyme involved in this mechanism is superoxide dismutase 2 (SOD2). The gene for this enzyme lies within a single haplotype block at 6q25.3, a region showing evidence for linkage to AD in a genome scan. We genotyped four single nucleotide polymorphisms (SNPs) in SOD2 in families of the National Institute of Mental Health-AD Genetics Initiative (ADGI): rs2758346 in the 5' untranslated region (UTR), rs4880 in exon 2, rs2855116 in intron 3 and rs5746136 in the 3'UTR. Under a dominant model, family-based association tests showed significant evidence for association of AD with the first three loci in a candidate gene set of families with individuals having age of onset of at least 50 years and two affected and one unaffected sibling, and in a late-onset subset of families (families with all affected individuals having age of onset of at least 65 years) from the full ADGI sample. The alleles transmitted more frequently to cases than expected under the null hypothesis were T, C, G, and G. Global tests of the transmission of haplotypes indicate that the first two loci have the most consistent association with risk of AD. Because of the high linkage disequilibrium in this small (14 kb) gene, and the presence of 100 SNPs in this gene, 26 of which may have functional significance, additional genotyping and sequencing are needed to identify the functionally relevant SNP. We discuss the importance of our findings and the relevance of SOD2 to AD risk.

An investigator-masked comparison of the efficacy and safety of twice daily applications of calcitriol 3 µg/g ointment vs. calcipotriol 50 µg/g ointment in subjects with mild to moderate chronic plaque-type psoriasis

BACKGROUND

Calcitriol and calcipotriol, two vitamin D derivatives, are available for topical treatment of psoriasis and have been shown to be effective.

AIM

To compare the efficacy and safety of calcitriol 3 microg/g and calcipotriol 50 microg/g.

METHODS

This was a multicentre, randomized, investigator-masked, and parallel comparison in subjects with mild to moderate chronic plaque-type psoriasis receiving either calcitriol or calcipotriol ointment twice daily for 12 weeks. Efficacy evaluations comprised global improvement (on a 4-point scale from 0: no change or worse, to 3: clear or almost clear) assessed by the investigator and by the subject. Efficacy further included the 'dermatological sum score' at each study visit. Safety evaluations included adverse event reporting, cutaneous safety assessed by the investigator and cutaneous discomfort assessment by the subject (both on a 5-point scale from 0: none, to 4: very severe).

RESULTS

A total of 250 subjects of both gender were recruited. At week 12, the LSmean score of global improvement rated by the investigator was 2.27 for calcitriol and 2.22 for calcipotriol. This difference was not statistically significant, with calcitriol demonstrating to be non-inferior to calcipotriol for global improvement. This same parameter was scored by the subject, with a mean of 2.12 for calcitriol and 2.09 for calcipotriol. The percentage of patients with at least marked improvement tended to be in favour of calcitriol (95.7% vs. 85% for calcipotriol). However, differences were not statistically significant. The mean worst score for the cutaneous safety assessment was higher in the calcipotriol group (0.3 vs. 0.1 and 0.4 vs. 0.2, by the investigator and the patient, respectively). These differences were statistically significant in favour of a better safety profile for calcitriol (P=0.0035). Fourteen dermatological and treatment-related adverse events were reported with calcipotriol vs. only five with calcitriol for a total of 22 adverse events reported throughout the study.

CONCLUSION

Calcitriol administered twice daily over a 12-week treatment period demonstrated similar efficacy to calcipotriol, while showing a significantly better safety profile.

Characterizing and Modelling of Fractured Reservoirs With Object-Oriented Global Optimization

Abstract

Modeling of naturally fractured reservoirs is the first step to develop best scenarios for hydraulic fracture treatment, the design of an optimum production method and to evaluate reservoir potential. This paper reviews the state-of-the-art in current methods; hence, presents an integrated modeling methodology, utilizing object-based modeling, stochastic simulation and global optimization. Firstly, as an object-based model, each fracture is presented and treated as a discrete object. A stochastic simulation is carried out to generate an initial fracture network. An objective function is then formulated as the difference in statistics between the initial network and the target. Semi-variogram and other spatial statistical properties (cross variogram, multi-histogram mean and variogram distance) of fracture parameters are included so that the objective function is able to statistically describe representative field data. Subsequently, we use a global optimization algorithm to optimize the objective function. A case study is performed on an actual outcrop fault map to illustrate the proposed methodology's capacity. The results map the outcrop faults very closely.

Introduction

Due to geological reasons, many of the naturally fractured reservoirs (NFR) possess very low permeability, which is inadequate for economic production. Therefore, some permeability enhancement techniques are essential for these reservoirs. However, the underlying principles of such techniques, such as hydraulic fracture stimulation, are complex and progress is hindered due to lack of appropriate geo-statistical fracture description models(1,2). Thus, there are three main reasons for a detailed fracture distribution:To site best locations for production wells;To study the response of natural fractures under stimulation pressure; hence, to develop a best scenario for hydraulic fracture treatment; andTo design an optimum production method and evaluate reservoir potential.

In order to achieve the prescribed objectives, NFR need to be characterized and modeled, which would include descriptions of reservoir boundaries, major faults and medium to small-scale fracture networks(3).

Fracture Modeling Techniques:

State-of-the-Art

Mathematical and Geo-Mechanical Models

Several techniques to simulate NFR have been documented in the literature. Firstly, there are mathematical and geo-mechanical models. Earlier mathematical methods to simulate NFR and fluid flow through them include equivalent continuum(4), discrete network(5) and hybrid models(6). The usual approach relies on simplistic geometrical descriptions of fracture systems (e.g. homogeneous reservoirs, parallel plate fractures, etc.) with primary efforts spent on flow behaviours(7). Many authors use different geo-mechanical approaches for modeling NFR, such as simple curvature analysis, field stress and fracture growth mechanism, and numerical analysis by solving systems of non-linear continuum mechanics equations using finite element methods(8).

However, due to the complex nature of fracture systems, most studies so far have succeeded only in modeling unrealistic homogeneous reservoirs. Moreover, most of these techniques use only a limited source of data, such as seismic or well logs. Hence, in modeling NFR, it is necessary to utilize all data sources in an integrated manner to reach a more comprehensive model(9).

Stochastic Simulation

Stochastic simulation is one of the integrated reservoir modeling approaches. Since explicit fracture information is only

Warfarin response and vitamin K epoxide reductase complex 1 in African Americans and Caucasians

The objective of this study was to determine whether two vitamin K epoxide reductase complex 1 (VKORC1) polymorphisms contribute to the variability in warfarin response, particularly in African Americans. The effect of the VKORC1 1173C/T and -1639G/A polymorphisms was examined in a prospective cohort study of 338 warfarin users. Subjects carrying an 1173T allele had a lower warfarin maintenance dose compared with subjects with the CC genotype in African Americans (-12.10 mg/week+/-4.93; P=0.02) and Caucasians (-14.41 mg/week+/-3.28; P<0.001). Before reaching maintenance dose, only Caucasians with the T allele had significantly increased risk of international normalized ratio >3 (odds ratio=3.10; 95% confidence interval: 1.73-5.55) compared with Caucasians with the CC genotype. Polymorphisms in the VKORC1 gene are associated with warfarin maintenance dose requirements among both African Americans and Caucasians. However, these polymorphisms may not be as useful in predicting over-anticoagulation among African Americans.

Apolipoprotein E genotype and warfarin dosing among Caucasians and African Americans

Warfarin sodium is a vitamin K antagonist that is plagued by large variability in patient response, including higher dose requirements among African Americans. Polymorphisms in the gene encoding apolipoprotein E (APOE) may partly explain this variability by altering transport of vitamin K to the liver. In a prospective cohort study of 232 individuals (52.2% Caucasian and 47.8% African American) initiating warfarin therapy, the weekly maintenance dose was significantly higher for African Americans than for Caucasians (mean 42.9 versus mean 36.9 mg, P=0.018), and the epsilon4 allele was more common among African Americans (37.8 versus 26.4% for Caucasians). In multivariable analyses, the presence of the epsilon4 allele was associated with a statistically significantly higher warfarin dose among African Americans (median 45.0 mg in epsilon4 carriers versus 35.0 mg in non-epsilon4 carriers, P=0.014) but not Caucasians (38.1 versus 35.0 mg, P=0.60). In addition, warfarin maintenance dose increased among African Americans according to genotype previously associated with differential hepatic chylomicron clearance (epsilon2/epsilon2 or epsilon2/epsilon3: 30.0 mg; epsilon3/epsilon3: 35.0 mg; epsilon3/epsilon4 or epsilon4/epsilon4: 45.0 mg; P=0.012), although the epsilon4/epsilon4 genotype was rare and not clearly associated with higher doses. The association of APOE with warfarin dosing was independent of CYP2C9 and VKORC1 polymorphisms. APOE polymorphisms thus may be important determinants of warfarin maintenance dose and could explain at least some of the observed racial differences in dose requirements.

Using an image-guided navigation system for localization of small pulmonary nodules before thoracoscopic surgery

BACKGROUND

Video-assisted thoracic surgery (VATS) provides a minimally invasive means to resect small pulmonary nodules (SPN). However, thoracoscopy has limits in the detection of small nodules, which are invisible and/or impalpable during surgery. Methods to localize such lesions, including methylene blue injection or the introduction of a hookwire under the guidance of computed tomography (CT), have some limitations. We are developing a new technique using image-guided navigation system for localization of small pulmonary nodules before thoracoscopic surgery.

METHODS

Four pigs underwent spiral-computed tomography (CT) scanning after they were given percutaneously created pulmonary lesions. The CT data were transmitted to a StealthStation navigation system, and with the help of the probe the lesions were located and resected under thoracoscopy.

RESULTS

A total of 20 lesions were created. Nodules were located at an average distance of 15.6 mm from the pleural surface. All the lesions were successfully localized, and biopsy specimens revealed successful resection of target material.

CONCLUSION

This method can provide appropriate guidance to small pulmonary nodules and prove effective in immediately facilitating subsequent thoracoscopic resection.

Use of beta-blockers for uncomplicated hypertension in the elderly: a cause for concern

Beta-blockers are less beneficial than other antihypertensive drugs in the elderly with hypertension. All elderly patients in Ontario, Canada (population over 3.5 million elderly) without co-morbidities who were first treated for hypertension with a beta-blocker were studied in a retrospective population-based cohort study (1994-2002) to determine the characteristics of those prescribed beta-blockers. Of the 194,761 patients in our cohort, 25 485 (13%) were prescribed a beta-blocker as their first antihypertensive agent. On multivariate analysis, factors significantly associated with being prescribed a beta-blocker as first-line therapy included male sex (adjusted odds ratio (OR) 1.06 [95% CI 1.03-1.09] vs women), younger age (adjusted OR 1.67 [95% CI 1.55-1.79] for patients aged 66-69 vs those aged 85 or older), residence in a long-term care facility (adjusted OR 1.19 [95% CI 1.04-1.35] vs living in the community) and lower socioeconomic status (adjusted OR 1.07 [95% CI 1.02-1.12], for lowest quintile vs highest quintile). Patients with diabetes were substantially less likely to be prescribed beta-blockers (adjusted OR 0.42 [95% CI 0.40-0.44]). Greater efforts are required to educate physicians to select other drugs for initial therapy in older patients with uncomplicated hypertension.

Theoretical and experimental studies on filtering tumor cells from blood cell mixtures with dam structure in microfluidic devices

Here, a filter with series of pools and dams structures was designed and fabricated, utilizing size difference between tumor and blood cells. The cell mixtures were successfully filtrated out by the filter, and separation efficiency was up to 99.9%. To evaluate the filter, physical models were made to describe the behaviors of different cells in microfluidic systems. As the ability of cell deformation depends on both cells' size and excess surface index (ESI), we measured the excess membrane area of different cells, and got tumor cell's ESI is 61.7% ~ 81% comparing with red blood cell (RBC) (44%) and white blood cell (WBC) (84%~137%). Then from the formulas we deduced, we get the filtering limitations of RBC, WBC, and tumor cell are respectively, around 1.8&#956;m, 1.0-1.6&#956;m and 3.7-4.4&#956;m for dam structure; and 1.3&#956;m, 0.9-1.3&#956;m and 3-3.4&#956;m radius for pipes, which actually show conditions for separation. The accuracy and high flux of the filter provide possibilities to isolate cancer cells directly from the blood in real-time, which could become a potential therapy to cancers.

Post-hybridisation by Electrophoresis for Reinforcing the Hybridization Result

In this paper, we developed an electrophoresis method for reinforcing hybridization efficiency, and distinguishing the perfectly matched sequences from the mismatched ones. The non-specific binding labeled targets in the hybridization were effectively removed by electrophoresis instead of the conventional washing procedure in the post-hybridisation process. During electrophoresis, the hybrids (the dual-spiral structures formed in hybridization) would be unchained when targets were continuously removed. In this case, not only the non-specific binding labeled targets, but also the targets participating in hybridization would be removed. Therefore, only the perfectly matched sequences had the distinct hybridization signals, the perfectly matched probes from the single-base mismatched ones could more easily be distinguished, and the single nucleotide polymorphisms (SNP) genotypes were also easily determined by dual-color fluorescence targets.

Improving Reliability of Response Prediction to Platinum-Based Therapy by AdaBoost and Multiple Classifiers

It is a challenge to construct a reliable classifier based on microarray gene expression data for prediction of chemotherapy response, because usually only a small number of samples are available and each sample has thousands of gene expressions. This paper uses boosting and bootstrap approaches to improve the reliability of prediction. Specifically, AdaBoost and multiple classifiers based methods are used, in which support vector machines (SVMs) are utilized as the classifiers due to their good generalization ability. We compare the performance of proposed methods with a single SVM classifier system using MAS gene expression dataset in prediction of the response to platinum-based therapy for advanced-stage ovarian cancers. Statistical tests show both of the proposed methods achieve better prediction performance and have good reliability in terms of mean and standard deviation of the prediction performance for different number of selected features.

A Simple Method of Fabricating Weir-type Filters with Interdigital Aligned Full-polymer Microfluidic Channels for Blood Cell Fractionation

This paper describes a new method to fabricate large scale 3D weir-type filter for cell fractionation. The 3D structure is realized by a conformal bonding of two separate PDMS (poly-dimethyloxane) layers with in-situ microchannels which are formed by the conventional soft lithographic techniques. Moreover, the microfluidics channels on the two PDMS are set to cross to each other to increase weir numbers and flow throughput. The gap space of the weir filters depends on the thickness of the photoresist coated for the master formation, thereby it can be defined as required from submicron to hundreds micron scale. A white blood cells (WBCs) extraction experiments with the full polymer fabricated filters are conducted to validate the proposed method.. The experimental results show that the weir-type filter array can fractionate the WBCs well from blood samples. Due to its intrinsic advantages of rapid process, high throughput and low cost, the proposed method is very promising for being integrated into Micro Total analysis System (&#956;TAS).