Culture conditions that influence accumulation of zwittermicin A by Bacillus cereus UW85

Bacillus cereus strain UW85 produces an antibiotic, designated zwittermicin A, that is associated with the ability of UW85 to suppress damping-off disease of alfalfa (Medicago sativa) caused by the oomycete pathogen, Phytophthora medicaginis, in a laboratory bioassay. We have identified certain culture conditions that promote or suppress zwittermicin A accumulation by UW85. Maximum accumulation was detected in supernatants of trypticase soy broth cultures after sporulation, which is when cultures of UW85 provide the greatest suppression of damping-off on alfalfa. Inorganic amendments to trypticase soy broth cultures had the following effects on zwittermicin A accumulation and disease suppression: phosphate (50 mM or more) reduced zwittermicin A accumulation and disease suppression; ferric iron (0.25–1.0 mM) enhanced zwittermicin A accumulaiton and disease suppression; micronutrients (manganese, boron, copper, molybdenum, zinc) had no effect on zwittermicin A accumulation or disease suppression. Cultures of UW85 grown in chemically defined minimal medium supplemented with casein hydrolysate or grown in defined medium containing the minimal requirements for growth supplemented with five amino acids (Gln, Arg, Met, Phe, Ile) accumulated zwittermicin A. In minimal medium, alfalfa seed exudate inhibited growth of UW85, whereas alfalfa sprout exudate enhanced zwittermicin A accumulation by 40%. These data indicate that the accumulation of zwittermicin A can be modulated by specific nutrients, inorganic compounds, and plant-derived factors. These results will facilitate the improvement of large-scale purification of zwittermicin A, suggest appropriate conditions under which to conduct further genetic and biochemical analyses, and further substantiate the association between antibiotic accumulation and disease suppression by UW85.     

The subcutaneous attachment of the monogenean Heterobothrium elongatum (Diclidophoridae) in the gills of Torquigener pleurogramma (Pisces: Tetraodontidae)

Heterobothrium elongatum predominantly occurred on the most anterior pair of gill arches of infected pufferfish, Torquigener pleurogramma. Juvenile and immature stages attached to gill lamellae and were concentrated on the ventral regions of the anterior pair of gill arches. Following penetration of subcutaneous tissues, young adult worms formed a subcutaneous channel either directly above or below the transverse septum, a tissue layer connecting the bases of adjacent gill rays. Large, sexually mature worms extended for most or all of the length of the gill arch where they filled the area normally occupied by the longitudinal lymphatic vessel (branchial vein) or lay adjacent to the efferent branchial and colateral arteries. Subcutaneous attachment by the parasite induced a marked inflammatory reaction in the host. During growth, the mid-region of the parasite became markedly elongate and formed a stalk connecting the haptor lying in the dorsal region of the gill and the body which emerged from the lower margin of the gill where penetration began.     

Exercise training in childhood-onset systemic lupus erythematosus: a controlled randomized trial

Introduction

Exercise training has emerged as a promising therapeutic strategy to counteract physical dysfunction in adult systemic lupus erythematosus. However, no longitudinal studies have evaluated the effects of an exercise training program in childhood-onset systemic lupus erythematosus (C-SLE) patients. The objective was to evaluate the safety and the efficacy of a supervised aerobic training program in improving the cardiorespiratory capacity in C-SLE patients.

Methods

Nineteen physically inactive C-SLE patients were randomly assigned into two groups: trained (TR, n = 10, supervised moderate-intensity aerobic exercise program) and non-trained (NT, n = 9). Gender-, body mass index (BMI)- and age-matched healthy children were recruited as controls (C, n = 10) for baseline (PRE) measurements only. C-SLE patients were assessed at PRE and after 12 weeks of training (POST). Main measurements included exercise tolerance and cardiorespiratory measurements in response to a maximal exercise (that is, peak VO₂, chronotropic reserve (CR), and the heart rate recovery (ΔHRR) (that is, the difference between HR at peak exercise and at both the first (ΔHRR1) and second (ΔHRR2) minutes of recovery after exercise).

Results

The C-SLE NT patients did not present changes in any of the cardiorespiratory parameters at POST (P > 0.05). In contrast, the exercise training program was effective in promoting significant increases in time-to-exhaustion (P = 0.01; ES = 1.07), peak speed (P = 0.01; ES = 1.08), peak VO₂ (P = 0.04; ES = 0.86), CR (P = 0.06; ES = 0.83), and in ΔHRR1 and ΔHRR2 (P = 0.003; ES = 1.29 and P = 0.0008; ES = 1.36, respectively) in the C-SLE TR when compared with the NT group. Moreover, cardiorespiratory parameters were comparable between C-SLE TR patients and C subjects after the exercise training intervention, as evidenced by the ANOVA analysis (P > 0.05, TR vs. C). SLEDAI-2K scores remained stable throughout the study.

Conclusion

A 3-month aerobic exercise training was safe and capable of ameliorating the cardiorespiratory capacity and the autonomic function in C-SLE patients.

Trial registration

NCT01515163.     

Automated Entire Thrombus Density Measurements for Robust and Comprehensive Thrombus Characterization in Patients with Acute Ischemic Stroke

Background and Purpose

In acute ischemic stroke (AIS) management, CT-based thrombus density has been associated with treatment success. However, currently used thrombus measurements are prone to inter-observer variability and oversimplify the heterogeneous thrombus composition. Our aim was first to introduce an automated method to assess the entire thrombus density and then to compare the measured entire thrombus density with respect to current standard manual measurements.

Materials and Method

In 135 AIS patients, the density distribution of the entire thrombus was determined. Density distributions were described using medians, interquartile ranges (IQR), kurtosis, and skewedness. Differences between the median of entire thrombus measurements and commonly applied manual measurements using 3 regions of interest were determined using linear regression.

Results

Density distributions varied considerably with medians ranging from 20.0 to 62.8 HU and IQRs ranging from 9.3 to 55.8 HU. The average median of the thrombus density distributions (43.5 ± 10.2 HU) was lower than the manual assessment (49.6 ± 8.0 HU) (p<0.05). The difference between manual measurements and median density of entire thrombus decreased with increasing density (r = 0.64; p<0.05), revealing relatively higher manual measurements for low density thrombi such that manual density measurement tend overestimates the real thrombus density.

Conclusions

Automatic measurements of the full thrombus expose a wide variety of thrombi density distribution, which is not grasped with currently used manual measurement. Furthermore, discrimination of low and high density thrombi is improved with the automated method.     

Towards a framework for the evolutionary genomics of Kinetoplastids: what kind of data and how much?

The current status of kinetoplastids phylogeny and evolution is discussed in view of the recent progresses on genomics. Some ideas on a potential framework for the evolutionary genomics of kinetoplastids are presented.     

The role of intravascular ultrasound imaging in vascular brachytherapy

Intracoronary brachytherapy has recently emerged as a new therapy to prevent restenosis. Initial experimental work was achieved in animal models and the results were assessed by histomorphometry. Initial clinical trials used angiography to guide dosimetry and to assess efficacy. Intravascular ultrasound (IVUS) permits tomographic examination of the vessel wall, elucidating the true morphology of the lumen and transmural components, which cannot be investigated on the lumenogram obtained by angiography. This paper reviews the use of IVUS in the clinical studies of brachytherapy conducted to date. IVUS allows clinicians to make a thorough assessment of the remodeling of the vessel and appears to have a major role to play in facilitating understanding of the underlying mechanisms of action in this emerging field. The authors propose that state-of-the-art IVUS techniques should be employed to further knowledge of the mechanisms of action of brachytherapy in atherosclerotic human coronary arteries.     

Improving model construction of profile HMMs for remote homology detection through structural alignment

Background  

Remote homology detection is a challenging problem in Bioinformatics. Arguably, profile Hidden Markov Models (pHMMs) are one of the most successful approaches in addressing this important problem. pHMM packages present a relatively small computational cost, and perform particularly well at recognizing remote homologies. This raises the question of whether structural alignments could impact the performance of pHMMs trained from proteins in the Twilight Zone, as structural alignments are often more accurate than sequence alignments at identifying motifs and functional residues. Next, we assess the impact of using structural alignments in pHMM performance.