Spatio-Temporal Monitoring of Benthic Anatoxin-a-Producing Tychonema sp. in the River Lech,Germany

Incidents with toxic benthic cyanobacteria blooms have been increasing recently. In 2019, several dogs were poisoned in the river Lech (Germany) by the benthic anatoxin-a-producing genus Tychonema. To characterize spatial and temporal distribution of potentially toxic Tychonema in this river, a systematic monitoring was carried out in 2020, focusing on the occurrence of the genus, its toxin production and habitat requirements. Tychonema and cyanobacterial community composition in benthic mats and pelagic samples were identified using a combined approach of microscopy and DNA sequencing of the 16S rRNA gene. In addition, anatoxin-a concentrations of selected samples were measured using the ELISA method. The habitat was characterized to assess the ecological requirements and growth conditions of Tychonema. Tychonema mats and anatoxin-a were detected at several sampling sites throughout the entire study period. Toxin concentrations increased with the progression of the vegetation period and with flow direction, reaching values between 0 and 220.5 µg/L. Community composition differed among pelagic and benthic samples, with life zone and substrate condition being the most important factors. The results of this study highlight the importance of monitoring and understanding the factors determining occurrence and toxin production of both pelagic and benthic cyanobacteria due to their relevance for the health of humans and aquatic ecosystems.     

Recent developments in human oocyte, embryo and blastocyst vitrification: where are we now?

The target of any cryopreservation procedure should be to ensure high survival rates of living cells after thawing. Two important parameters determine the success of any cryopreservation protocol: the manner in which cells regain equilibrium in response to cooling, and the speed of freezing (cooling rate). Slow-rate freezing protocols result in the formation of ice crystals during cooling and warming. Vitrification, in which high cooling rates in combination with a high concentration of cryoprotectant are used, does not produce any ice crystals during cooling and warming. However, there is a practical limit to the attainable cooling speed, and also a biological limit to the concentration of cryoprotectant tolerated by the cells during vitrification. Although post-warming survival depends on the species, the developmental stage and the quality of the embryos being vitrified, it seems clear that vitrification methods are increasingly successful and might be a better method than slow cooling procedures in the field of cryobiology. Many of the potential problems and benefits underlying vitrification as a method of choice for embryo cryopreservation in clinical embryology will be discussed in this review.     

Enzymatically degraded Eurylon 6 HP-PG: ethylcellulose film coatings for colon targeting in inflammatory bowel disease patients

Objectives Film coatings based on blends of Eurylon 6 HP‐PG (a hydroxypropylated and pregelatinized high amylose starch) and ethylcellulose were to be evaluated as promising coating materials for site‐specific drug delivery to the colon of patients suffering from inflammatory bowel diseases. Methods Pellet starter cores containing 60% 5‐aminosalicylic acid were prepared by extrusion/spheronization and coated with different Eurylon 6 HP‐PG : ethylcellulose blends at various coating levels. Drug release was measured in media simulating the contents of the upper gastrointestinal tract (in the presence and absence of enzymes) as well as in media simulating the contents of the colon. Key findings 5‐Aminosalicylic acid release could effectively be suppressed in 0.1 N HCl and phosphate buffer pH 6.8, optionally containing pepsin or pancreatin, but occurred as soon as the pellets came into contact with culture medium inoculated with faecal samples from inflammatory bowel disease patients. This can be attributed to the partial degradation of the starch derivative by enzymes secreted by bacteria present in the colon of these patients. Conclusions The presented drug delivery system is adapted to the pathophysiological conditions in inflammatory bowel disease patients. Furthermore, drug release remained unaltered upon 1 year open storage.     

A technical concept of a computer game for patients with Parkinson's disease – a new form of PC-based physiotherapy

Background: At present, there are no meaningful and sophisticated computer games that simultaneously allow the treatment of movement disorders such as Parkinson's syndrome. In particular, there are no systems to consider the severity of the disease and the physical skills of the patient.

Methods: A computer game using the Microsoft Kinect as markerless sensor for the 3?D recognition of the patient’s movement was developed to support the rehabilitation. The scenario of a basketball game was created after determining that the movement like throwing a ball and the correct posture of the body are important. A study based on system usability was performed with 15 patients to evaluate the system.

Results: The technical feasibility of a computer-assisted training system for supporting patients with Parkinson‘s disease has been demonstrated. No markers on the patient are required for movement detection and allow a user-friendly handling. Regarding the usability study, the patients were accepting of such a system and its at-home use and symptoms like ‘freezing’ and the Pisa syndrome can be treated.

Conclusions: The physiotherapist can be assisted by the developed rehabilitation system. An objective measurement of the patient’s training progress delivers valuable information to adjust the training sessions for every patient individually. Due to its modular character, the system can also be applied to other diseases or sports injuries and offers the basis for further development.     

Multidetector-row computed tomography and magnetic resonance imaging of atherosclerotic lesions in human ex vivo coronary arteries

In the present study, we tested the ability of multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI) to identify and retrospectively characterize atherosclerotic lesions in human ex vivo coronary arteries. Thirteen ex vivo hearts were studied with MDCT and MRI. MDCT-images were obtained with an isotropic voxel size of 0.6mm(3). MR images were obtained with an in-plane resolution of 195 microm and 3mm slice thickness. All images were matched with histopathology sections. For both modalities, the sensitivity for the detection of any atherosclerotic lesion was evaluated, and a retrospective analysis of plaque morphology according to criteria defined by the American Heart Association (AHA) was performed. At histopathology, 28 atherosclerotic lesions were found. 21 and 23 of these lesions were identified by MDCT and MRI, respectively. Both modalities detected a small number of false-positive lesions. After retrospective matching with histopathology, MDCT as well as MRI were able to differentiate typical morpholocigal features for fatty, fibrous or calcified plaque components. Using the information presented in this study, in vivo coronary artery wall imaging using MDCT as well as MRI could be facilitated and supported for future investigations on this subject.     

Osteoprotegerin gene polymorphisms in men with coronary artery disease

Osteoprotegerin (OPG) antagonizes receptor activator of nuclear factor-kappaB ligand (RANKL), the principal regulator of osteoclasts. Of note, OPG-deficient mice display osteoporosis and arterial calcification. Recently, OPG gene polymorphisms have been associated with osteoporosis and early predictors of cardiovascular disease. In this study, we examined OPG gene polymorphisms in 468 men who had absence of coronary artery disease (CAD) or single-, double-, or triple-vessel disease on coronary angiography. Denaturing gradient gel electrophoresis followed by DNA sequencing revealed nucleotide substitutions 149 T-->C, 163 A-->G, 209 G-->A, 245 T-->G, 950 T-->C (all promoter), 1181 G-->C (exon 1), and 6890 A-->C (intron 4), respectively. Although single polymorphisms were not associated with CAD, linkage of polymorphisms 950 and 1181 revealed that haplotypes were overrepresented in men with CAD (chi(2) = 17.05; P = 0.03) with an increased risk of CAD in carriers of genotypes 950 TC/1181 GC and 950 CC/1181 CC (odds ratio, 1.67; 95% confidence interval, 1.02-2.72; P = 0.04). Furthermore, serum OPG levels were correlated with the presence of a C allele at position 950 (P = 0.02). In summary, linkage of genetic variations of the OPG gene at positions 950 and 1181 may confer an increased risk of CAD in Caucasian men.     

Insufficient tissue ablation by rotational atherectomy leads to worse long-term results in comparison with balloon angioplasty alone for the treatment of diffuse in-stent restenosis: insights from the intravascular ultrasound substudy of the ARTIST randomized multicenter trial.

The ARTIST trial demonstrated a worse outcome for patients with in-stent restenosis (ISR) treated with rotational atherectomy (RA) and adjunctive balloon angioplasty (PTCA) as compared to PTCA alone. This intravascular ultrasound (IVUS) substudy compares effects of lumen enlargement and examines reasons for failure of RA in this setting. IVUS (n = 56) was performed after each interventional step and at follow-up. Volumetric lumen gain measured 79 +/- 68 mm(3) after PTCA (13 +/- 4 atm) as compared to 44 +/- 26 mm(3) after RA and adjunctive PTCA (7 +/- 3 atm; P < 0.0001). RA itself enlarged lumen by only 19 +/- 17 mm(3) and stent volume was 47% smaller as compared to high-pressure PTCA. Low-pressure strategy after RA did not prevent tissue growth during follow-up (19 +/- 25 vs. 36 +/- 38 mm(3); RA vs. PTCA; P = 0.09). Consequently, net lumen gain after PTCA was 82% higher compared to RA (46 +/- 54 vs. 25 +/- 24 mm(3); P = 0.09). Further stent expansion is the key mechanism to achieve luminal gain by PTCA of ISR. Neointimal ablation by RA has only minor effects. Low-pressure PTCA does not prevent recurrent tissue growth and failed for treatment of ISR due to insufficient stent expansion.