The microbiotest battery as an important component in the assessment of snowmelt toxicity in urban watercourses—preliminary studies

The aim of the study was to use a battery of biotests composed of producers (Selenastrum capricornutum, Sorghum saccharatum, Lepidium sativum, and Sinapis alba), consumers (Thamnocephalus platyurus), and decomposers (Tetrahymena thermophila) to evaluate the toxicity of snowmelt and winter storm water samples. The toxicity of the samples collected in the winter period December to February (2010–2011), in one of the largest agglomerations in Poland, the city of Lodz, was compared to that of storm water samples taken under similar conditions in June. The most toxic snowmelt samples were found to be high acute hazard (class IV), while the remaining samples were rated as slight acute hazard (class II). L. sativum (in the Phytotox test) was the most sensitive test organism, giving 27 % of all toxic responses, followed by S. capricornutum with 23 % of all responses. T. thermophila was the least sensitive, with only 2 % of all toxic responses. The greatest range of toxicity was demonstrated by samples from the single family house catchment: no acute hazard (class I) to high acute hazard (class IV

Bacteria homologus to Aeromonas capable of microcystin degradation

Water blooms dominated by cyanobacteria are capable of producing hepatotoxins known as microcystins. These toxins are dangerous to people and to the environment. Therefore, for a better understanding of the biological termination of this increasingly common phenomenon, bacteria with the potential to degrade cyanobacteria-derived hepatotoxins and the degradative activity of culturable bacteria were studied. Based on the presence of the mlrA gene, bacteria with a homology to the Sphingopyxis and Stenotrophomonas genera were identified as those presenting potential for microcystins degradation directly in the water samples from the Sulejów Reservoir (SU, Central Poland). However, this biodegrading potential has not been confirmed in in vitro experiments. The degrading activity of the culturable isolates from the water studied was determined in more than 30 bacterial mixes. An analysis of the biodegradation of the microcystin-LR (MC-LR) together with an analysis of the phylogenetic affiliation of bacteria demonstrated for the first time that bacteria homologous to the Aeromonas genus were able to degrade the mentioned hepatotoxin, although the mlrA gene was not amplified. The maximal removal efficiency of MC-LR was 48%. This study demonstrates a new aspect of interactions between the microcystin-containing cyanobacteria and bacteria from the Aeromonas genus.The authors would like to acknowledge the European Cooperation in Science and Technology, COST Action ES 1105 “CYANOCOST - Cyanobacterial blooms and toxins in water resources: Occurrence, impacts and management” for adding value to this study through networking and knowledge sharing with European experts and researchers in the field. The Sulejów Reservoir is a part of the Polish National Long- Term Ecosystem Research Network and the European LTER site

Četiri nove vrste roda Aceria (Acari: Eriophyoidea) iz Srbije

Four new species of eriophyoid mites within the genus Aceria, from Serbia are described and illustrated: A. cichorii n. sp. causing 'witches broom' on Cichorium intybus L. (Asteraceae), A. matricariae n. sp. free living in flower heads of Matricaria chamomilla L. (Asteraceae), A. cirsii n. sp. free living on Cirsium rivulare (Jacq.) All. (Asteraceae) and A. carduui n. sp. free living on Carduus personata (L.) Jacq. (Asteraceae).U radu su opisane četiri nove vrste eriofida iz roda Aceria (Acari Erophyoidea): Aceria cichorii n. sp. ca Cichorium intybus L., A. matricariae n. sp. sa Matricaria chamomilla L., A. cirsii n. sp. sa Cirsium rivulare (Jacq.) All. i A. carduui n. sp. sa Carduus personata (L.) Jacq. Nove vrste su nacrtane i opisane, a priložene je i diferencijalna dijagnoza u odnosu na Aceria baccharices K., A. chondrillae (Can.), A. anthocoptes (Nal.) i A. balasi Farkas

Novel Timothy Syndrome Mutation Leading to Increase in CACNA1C Window Current

Background Timothy syndrome (TS) is a rare multisystem genetic disorder characterized by a myriad of abnormalities, including QT prolongation, syndactyly, and neurologic symptoms. The predominant genetic causes are recurrent de novo missense mutations in exon 8/8A of the CACNA1C-encoded L-type calcium channel; however, some cases remain genetically elusive. Objective The purpose of this study was to identify the genetic cause of TS in a patient who did not harbor a CACNA1C mutation in exon 8/A, and was negative for all other plausible genetic substrates. Methods Diagnostic exome sequencing was used to identify the genetic substrate responsible for our case of TS. The identified mutation was characterized using whole-cell patch-clamp technique, and the results of these analyses were modeled using a modified Luo–Rudy dynamic model to determine the effects on the cardiac action potential. Results Whole exome sequencing revealed a novel CACNA1C mutation, p.Ile1166Thr, in a young male with diagnosed TS. Functional electrophysiologic analysis identified a novel mechanism of TS-mediated disease, with an overall loss of current density and a gain-of-function shift in activation, leading to an increased window current. Modeling studies of this variant predicted prolongation of the action potential as well as the development of spontaneous early afterdepolarizations. Conclusion Through expanded whole exome sequencing, we identified a novel genetic substrate for TS, p.Ile1166Thr-CACNA1C. Electrophysiologic experiments combined with modeling studies have identified a novel TS mechanism through increased window current. Therefore, expanded genetic testing in cases of TS to the entire CACNA1C coding region, if initial targeted testing is negative, may be warranted

Human Small Heat Shock Protein B8 Inhibits Protein Aggregation without Affecting the Native Folding Process

: Small Heat Shock Proteins (sHSPs) are key components of our Protein Quality Control system and are thought to act as reservoirs that neutralize irreversible protein aggregation. Yet, sHSPs can also act as sequestrases, promoting protein sequestration into aggregates, thus challenging our understanding of their exact mechanisms of action. Here, we employ optical tweezers to explore the mechanisms of action of the human small heat shock protein HSPB8 and its pathogenic mutant K141E, which is associated with neuromuscular disease. Through single-molecule manipulation experiments, we studied how HSPB8 and its K141E mutant affect the refolding and aggregation processes of the maltose binding protein. Our data show that HSPB8 selectively suppresses protein aggregation without affecting the native folding process. This anti-aggregation mechanism is distinct from previous models that rely on the stabilization of unfolded polypeptide chains or partially folded structures, as has been reported for other chaperones. Rather, it appears that HSPB8 selectively recognizes and binds to aggregated species formed at the early stages of aggregation, preventing them from growing into larger aggregated structures. Consistently, the K141E mutation specifically targets the affinity for aggregated structures without impacting native folding, and hence impairs its anti-aggregation activity

Novel pathogenic variant in TGFBR2 confirmed by molecular modeling is a rare cause of Loeys-Dietz syndrome

Loeys-Dietz syndrome (LDS) is a connective tissue disorder characterized by vascular findings of aneurysm and/or dissection of cerebral, thoracic, or abdominal arteries and skeletal findings. We report a case of a novel pathogenic variant in TGFBR2 and phenotype consistent with classic LDS. The proband was a 10-year-old presenting to the genetics clinic with an enlarged aortic root (Z-scores 5-6), pectus excavatum, and congenital contractures of the right 2nd and 3rd digit. Molecular testing of TGFBR2 was sent to a commercial laboratory and demonstrated a novel, likely pathogenic, variant in exon 4, c.1061T>C, p.(L354P). Molecular modeling reveals alteration of local protein structure as a result of this pathogenic variant. This pathogenic variant has not been previously reported in LDS and thus expands the pathogenic variant spectrum of this condition