Circulating microRNAs in Patients with Shiga-Toxin-Producing E. coli O104:H4 Induced Hemolytic Uremic Syndrome

Background

In early May 2011, an outbreak of hemorrhagic colitis associated with hemolytic–uremic syndrome (HUS) first developed in Northern Germany and spread to 15 other countries in Europe. The outbreak-strain O104:H4, which combined virulence factors of typical enteroaggregative and Shiga-Toxin–producing E. coli was associated with an unusual high rate of hemolytic uremic syndrome. Also an unexpected high rate of coma and seizures leading to mechanical ventilation and ICU treatment was observed. MicroRNAs are small ribonucleotides orchestrating gene expression. We tested whether circulating microRNAs in serum of HUS patients during the 2011 epidemics are altered in this patient cohort and related to clinical manifestations.

Methodology/Principal Findings

We profiled microRNAs using RNA isolated from serum of patients and healthy age-matched controls. The results were validated in 38 patients at baseline, 29 patients during follow-up and 21 age-matched healthy controls by miRNA-specific quantitative RT-PCR. Circulating levels of miR-24, miR-126 were increased in HUS patients versus controls. There was no association between these microRNAs and renal function or the need for renal replacement therapy. In contrast, levels of miR-126 were associated with neurological symptoms at baseline and during follow-up. In addition, miR-126 (on admission) and miR-24 (on admission and during follow-up) were associated with platelet count.

Conclusions/Significance

Circulating microRNAs are strongly altered in this patient cohort and associated with neurological symptoms as well as platelet count.     

Structural investigation of catalytically modified F120L and F120Y semisynthetic ribonucleases.

The structures of two catalytically modified semisynthetic RNases obtained by replacing phenylalanine 120 with leucine and tyrosine have been determined and refined at a resolution of 2.0 A (R = 0.161 and 0.184, respectively). These structures have been compared with the refined 1.8-A structure (R = 0.204) of the fully active phenylalanine-containing enzyme (Martin PD, Doscher MS, Edwards BFP, 1987, J Biol Chem 262:15930-15938) and with the catalytically defective D121A (2.0 A, R = 0.172) and D121N (2.0 A, R = 0.186) analogs (deMel VSJ, Martin PD, Doscher MS, Edwards BFP, 1992, J Biol Chem 267:247-256). The movement away from the active site of the loop containing residues 65-72 is seen in all three catalytically defective analogs--F120L, D121A, and D121N--but not in the fully active (or hyperactive) F120Y. The insertion of the phenolic hydroxyl of Tyr 120 into a hydrogen-bonding network involving the hydroxyl group of Ser 123 and a water molecule in F120Y is the likely basis for the hyperactivity toward uridine 2',3'-cyclic phosphate previously found for this analog (Hodges RS, Merrifield RB, 1974, Int J Pept Protein Res 6:397-405) as well as the threefold increase in KM for cytidine 2',3'-cyclic phosphate found for this analog by ourselves.     

The Effectiveness of Riparian ‘Restoration’ on Water Quality—A Case Study of Lowland Streams in Canterbury,New Zealand

In New Zealand, around half of the lowland water bodies do not meet water quality standards, primarily due to widespread changes in land use. Riparian restoration has been occurring in New Zealand for over 30 years in an effort to minimize this impact, however, little monitoring of restoration effectiveness has been undertaken. This study evaluated the impact of riparian plantings on water quality of lowland streams in the Lake Ellesmere catchment. A paired‐catchment design on four river reaches was used to compare restored riparian buffers with control sites upstream. Chemical water quality sampling was used in conjunction with a macroinvertebrate community assessment. Equivocal benefits of riparian restoration were observed, with improvements in some variables but not in others. Riparian restoration had a positive effect on water quality in terms of increasing dissolved oxygen and decreasing turbidity. However, conductivity increased at planted sites and no changes were observed in other variables. These findings may be affected by the insufficient width of all four buffers, and gaps in the buffer system contributing to poor water quality. Although variable responses were seen in invertebrate community composition, this research suggests that even narrow planted buffer strips may be effective in improving some water quality parameters. The overall mixed results present a fair assessment of the benefits of riparian restoration that may be expected within a relatively short time following vegetation establishment. Even when no baseline data have been established prior to restoration, this research showed monitoring can demonstrate the effectiveness of riparian restoration.     

Polymorphisms in the glucocorticoid receptor gene that modulate glucocorticoid sensitivity are associated with rheumatoid arthritis

Introduction  

The glucocorticoid receptor (GR) plays an important regulatory role in the immune system. Four polymorphisms in the GR gene are associated with differences in glucocorticoid (GC) sensitivity; the minor alleles of the polymorphisms N363 S and BclI are associated with relative hypersensitivity to GCs, while those of the polymorphisms ER22/23EK and 9β are associated with relative GC resistance. Because differences in GC sensitivity may influence immune effector functions, we examined whether these polymorphisms are associated with the susceptibility to develop Rheumatoid Arthritis (RA) and RA disease severity.     

Glucocorticoid receptor gene polymorphisms and disease activity during pregnancy and the postpartum period in rheumatoid arthritis

Introduction

The mechanism underlying the spontaneous improvement of rheumatoid arthritis (RA) during pregnancy and the subsequent postpartum flare is incompletely understood, and the disease course varies widely between pregnant RA patients. In pregnancy, total and free levels of cortisol increase gradually, followed by a postpartum decrease to prepregnancy values. The glucocorticoid receptor (GR) polymorphisms BclI and N363S are associated with relatively increased glucocorticoid (GC) sensitivity, whereas the 9β and ER22/23EK polymorphisms of the GR gene are associated with a relatively decreased GC sensitivity. We examined the relation between the presence of these GR polymorphisms and level of disease activity and disease course of RA during pregnancy and postpartum.

Methods

We studied 147 participants of the PARA study (Pregnancy-Induced Amelioration of Rheumatoid Arthritis study), a prospective study investigating the natural improvement during pregnancy and the postpartum flare in women with RA. Patients were visited, preferably before pregnancy, at each trimester and at three postpartum time points. On all occasions, disease activity was scored by using DAS28. All patients were genotyped for the GR polymorphisms BclI, N363S, 9β, and ER22/23EK and divided in groups harboring either polymorphisms conferring increased GC sensitivity (BclI and N363S; GC-S patients) or polymorphisms conferring decreased GC sensitivity (9β or 9β + ER22/23EK; GC-I patients). Data were analyzed by using a mixed linear model, comparing GC-S patients with GC-I patients with respect to improvement during pregnancy and the postpartum flare. The cumulative disease activity was calculated by using time-integrated values (area under the curve, AUC) of DAS28 in GC-I patients versus GC-S patients. Separate analyses were performed according to the state of GC use.

Results

GC-S patients treated with GC had a significantly lower AUC of DAS28 in the postpartum period than did GC-I patients. This difference was not observed in patients who were not treated with GCs. During pregnancy, GC-S and GC-I patients had comparable levels of disease activity and course of disease.

Conclusions

Differences in relative GC sensitivity, as determined by GR polymorphisms, are associated with the level of disease activity in the postpartum period in GC-treated patients, but they do not seem to influence the course of the disease per se.     

ImageParser: a tool for finite element generation from three-dimensional medical images

Background

The finite element method (FEM) is a powerful mathematical tool to simulate and visualize the mechanical deformation of tissues and organs during medical examinations or interventions. It is yet a challenge to build up an FEM mesh directly from a volumetric image partially because the regions (or structures) of interest (ROIs) may be irregular and fuzzy.

Methods

A software package, ImageParser, is developed to generate an FEM mesh from 3-D tomographic medical images. This software uses a semi-automatic method to detect ROIs from the context of image including neighboring tissues and organs, completes segmentation of different tissues, and meshes the organ into elements.

Results

The ImageParser is shown to build up an FEM model for simulating the mechanical responses of the breast based on 3-D CT images. The breast is compressed by two plate paddles under an overall displacement as large as 20% of the initial distance between the paddles. The strain and tangential Young's modulus distributions are specified for the biomechanical analysis of breast tissues.

Conclusion

The ImageParser can successfully exact the geometry of ROIs from a complex medical image and generate the FEM mesh with customer-defined segmentation information.

     

Structural changes that accompany the reduced catalytic efficiency of two semisynthetic ribonuclease analogs.

The structures of two catalytically defective semi-synthetic RNases obtained by replacing aspartic acid 121 with asparagine or alanine have been determined and refined at a resolution of 2.0 A (R = 0.186 and 0.172, respectively). When these structures are compared with the refined 1.8-A structure (R = 0.204) of the fully active aspartic acid-containing enzyme (Martin, P.D., Doscher, M.S., and Edwards, B. F. P. (1987) J. Biol. Chem. 262, 15930-15938), numerous and widespread changes, much greater in number and magnitude than the small structural variations noted previously between the semisynthetic complex and RNase A, are found to have occurred. These changes include the movement of the loop containing residues 65-72 away from the active site, a more or less generalized relocation of crystallographically bound water molecules, and a number of rearrangements in the hydrogen bonding network at the active site. Most changes are far removed from the immediate site of the modifications and are distributed essentially throughout the molecule. The details of many of these changes are unique to each analog. In the asparagine analog, a destabilization in the positioning of active site residue His-119 also appears to have occurred.     

The effects of short-term unilateral and bilateral lower-body resistance training on measures of strength and power

The purpose of this study was to compare the effects of short-term unilateral resistance training (UL) and bilateral resistance training (BL) with free weights on several tests of unilateral and bilateral lower-body strength and power in men and women. Thirty-eight untrained men and women (mean body mass 78.3 +/- 21.47 kg; age 20.74 +/- 2.6 years) completed the study. The groups trained 2 days per week for 8 weeks with free weights and 2 days per week for 5 of the 8 weeks with plyometric drills. The resistance-training program consisted of a progression from 3 sets of 15 repetitions at 50% of the subject's predicted 1 repetition maximum (1RM) to 6 sets of 5 repetitions at 87% 1RM. Training volume and intensity were equal for each group. The free-weight squat was used to measure unilateral and bilateral strength. Power was measured by the Magaria-Kalamen stair-climb test and the unilateral and bilateral vertical jump test. Analysis of covariance was used to analyze differences between men and women and the interaction of group and gender. Pretest scores were used as the covariate. The UL group improved more than the BL group on the unilateral vertical jump height (p = 0.001) and relative power (p = 0.013). After adjusting for pretest differences, the improved scores on all tests, except for the unilateral squat, were similar between the men and the women. No significant interactions on all tests were found for the men or women comparison between training groups. These results indicate that UL and BL are equally effective for early phase improvement of unilateral and bilateral leg strength and power in untrained men and women.     

The validity and reliability of the 1RM bench press using chain-loaded resistance

The purposes of this study were to determine the validity and test-retest reliability of the 1 repetition maximum (1RM) chain-loaded, free-weight bench press (CBP) and to examine possible learning effects that may occur between the test-retest measurements. Nine resistance-trained men (20.58 +/- 1.31 years, 188.24 +/- 9.29 cm, 92.07 +/- 16.94 kg) and seven resistance-trained women (20.42 +/- 0.98 years, 175.61 +/- 9.32 cm, 73.61 +/- 10.80 kg) participating in Division II college basketball completed this study. Two familiarization sessions took place using light to moderate loads to learn proper technique. The subjects completed a 1RM test on the traditional plate-loaded bench press 4 days before completion of the CBP 1RM, which was followed by 4 days of rest before completing the retest. Intraclass correlation coefficients (ICC) and the percent coefficients of variation (CV) were used to determine relative and absolute test-retest reliability. Concurrent validity was determined from the Pearson correlation coefficients between the CBP and the plate-loaded bench press. Test-retest differences were analyzed with the paired t-test. ICC and CV for the men (r = 0.99, 1.4%) and women (r = 0.93, 3.5%), respectively indicate that highly reproducible 1RM scores can be found with the CBP. High validity was also found with high correlations between the CBP and plate-loaded bench press for the men (r = 0.95) and women (r = 0.80). A statistically significant (p = 0.04) but clinically small (2.57 kg) shift in the mean occurred between the CBP test and retest for the men, whereas no change occurred for the women. The data indicate that valid and reliable 1RM scores can be found after two familiarization sessions in men and women athletes who have previous resistance training experience.