Mirabegron, a Selective β3-Adrenergic Receptor Agonist, as a Potential Anti-Obesity Drug

Obesity is becoming a global health epidemic. Brown and "beige" adipose tissue may produce heat, leading to energy expenditure enhancement and weight loss. Mirabegron, a selective β3-adrenergic receptor agonist, has been found to be effective as a brown adipose tissue activator, a "beige" cells stimulator and a metabolic homeostasis controller in animal and human studies. Although in animal studies, administration of mirabegron led to obesity improvement, significant weight loss in obese patients after mirabegron treatment has not been demonstrated so far, which may be associated with the too-short duration of the trials and the small number of participants in the studies. In humans, the most effective treatment for adipose tissue stimulation was high doses of mirabegron; however, cardiovascular side effects may limit the use of such doses, so the long-term safety must be evaluated. In cases of tachycardia or blood pressure elevation, the co-administration of a β1-adrenergic receptor blocker may be useful. It should be checked whether smaller doses of mirabegron, taken for a longer time, will be sufficient to stimulate brown and "beige" adipose tissue, leading to weight loss. The introduction of mirabegron into obesity treatment in the future will require long-term trials with larger numbers of subjects, to assess mirabegron efficacy, tolerability, and safety.

Inter-comparison of marine microbiome sampling protocols

Research on marine microbial communities is growing, but studies are hard to compare because of variation in seawater sampling protocols. To help researchers in the inter-comparison of studies that use different seawater sampling methodologies, as well as to help them design future sampling campaigns, we developed the EuroMarine Open Science Exploration initiative (EMOSE). Within the EMOSE framework, we sampled thousands of liters of seawater from a single station in the NW Mediterranean Sea (Service d'Observation du Laboratoire Arago [SOLA], Banyuls-sur-Mer), during one single day. The resulting dataset includes multiple seawater processing approaches, encompassing different material-type kinds of filters (cartridge membrane and flat membrane), three different size fractionations (>0.22 µm, 0.22-3 µm, 3-20 µm and >20 µm), and a number of different seawater volumes ranging from 1 L up to 1000 L. We show that the volume of seawater that is filtered does not have a significant effect on prokaryotic and protist diversity, independently of the sequencing strategy. However, there was a clear difference in alpha and beta diversity between size fractions and between these and "whole water" (with no pre-fractionation). Overall, we recommend care when merging data from datasets that use filters of different pore size, but we consider that the type of filter and volume should not act as confounding variables for the tested sequencing strategies. To the best of our knowledge, this is the first time a publicly available dataset effectively allows for the clarification of the impact of marine microbiome methodological options across a wide range of protocols, including large-scale variations in sampled volume.

Bioaccumulation of PCBs, HCB and PAHs in the summer plankton from West Spitsbergen fjords

Concentrations of seven polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and twelve polycyclic aromatic hydrocarbons (PAHs) were examined in plankton collected in summer from different Arctic fjords (Hornsund, Kongsfjorden, Adventfjorden). The levels of all target contaminants in arctic protists have been analyzed for the first time. This is also the first report on PAH levels in arctic fjords zooplankton. ∑7 PCB, HCB and ∑12 PAH concentrations were up to 3.58 ng/g w.w., 0.28 ng/g w.w. and 249 ng/g w.w., respectively. Among the zooplankton species, the highest concentrations of the most analyzed contaminants were detected in Themisto abyssorum. This could be explained by the predatory feeding strategy of this species. The importance of diet was confirmed by the low concentrations of contaminants detected in the herbivorous copepod Calanus spp. Depending on contaminant, bioaccumulation occurred in 50 to 100% studied cases. Studies have shown significant biomagnification of PCBs and PAHs in zooplankton predator-prey pairs.

Synthesis, structure, properties and antimicrobial activity of para trifluoromethyl phenylboronic derivatives

The [2-formyl-4-(trifluoromethyl)phenyl]boronic acid as well as its benzoxaborole and bis(benzoxaborole) derivatives were obtained and their properties studied. The 2-formyl compound displays an unusual structure in the crystalline state, with a significant twist of the boronic group, whereas in DMSO solution it tautomerizes with formation of a cyclic isomer. All the studied compounds exhibit relatively high acidity as well as a reasonable antimicrobial activity. Docking studies showed interactions of all the investigated compounds with the binding pocket of Candida albicans LeuRS. High activity against Bacillus cereus was determined for the 2-formyl compound as well as for the novel bis(benzoxaborole), whereas the studied benzoxaborole shows high antifungal action with MIC values equal to 7.8and 3.9 μg/mL against C. albicans and A. niger respectively. None of the studied compounds exhibits reasonable activity against E. coli.

The interplay between plankton and particles in the Isfjorden waters influenced by marine- and land-terminating glaciers

Climate-induced glacial retreat in the Arctic results in an increased supply of meltwater with suspended terrigenous material into the marine environment. Despite increasing research efforts, effects of glacial retreat on functioning of plankton are not well documented and understood. Thus, we studied a hydro-optical seawater regime along with particle/plankton concentrations and composition structure in a high Arctic fjord (Isfjorden, West Spitsbergen) during mid-summer in 2019. This comprehensive study of the upper 50 m water layer presented a sharp distinction between 'muddy' waters influenced by glacial and river runoff and 'clear' open fjordic waters in the form of a notable difference in chlorophyll a concentrations, extent of euphotic zone depth, turbidity, inorganic/organic particle concentrations, and water colour. In this study, we present that the effects of glacial retreat on Arctic pelagial depend not only on different types of glaciers (marine- and land-terminating), but presumably, also on fjord topography and exposure to oceanic water inflow. The contrasting glacial, hydrological, and topographical conditions had different effects on the share of zooplankton and marine snow. Despite adaptation of the planktonic communities in the Arctic to high sediment loads and resultant light limitations, our study shows that continuing retreat of tidewater glaciers will have negative effect on planktonic communities especially in enclosed shallow fjord branches. Moreover, seawater darkening due to high turbidity could negatively affect tactile predators, such as gelatinous zooplankton. Additional division of plankton into functional groups typically used in the biogeochemical models demonstrated that diatoms, flagellates and mesozooplankton are influenced by suspended matter, whereas microzooplankton are highly adaptive to increased sediment loads. Since we investigated the largest Svalbard fjord system and incorporated multiple components of the pelagic realm, the current study delivers important recommendations for including marine snow and gelatinous zooplankton in ecosystem models applied in polar regions.

Thyroid diseases in patients with acromegaly

Acromegaly often involves the presence of different pathologies of the thyroid gland. Long-lasting stimulation of the follicular epithelium by growth hormone (GH) and insulin-like growth factor 1 (IGF-1) can cause disorders in thyroid function, an increase in its mass and the development of goitre. Acromegalic patients present most frequently with non-toxic multinodular goitre. Nodules are more prevalent in patients with active acromegaly. It has been suggested that then thyroid size increases and it can be reduced through treatment with somatostatin analogues. The relationship between thyroid volume and the level of IGF-1 and the duration of the disease is unclear. Each acromegalic patient requires a hormonal and imaging evaluation of the thyroid when the diagnosis is made, and an accurate evaluation during further observation and treatment. Although the data concerning the co-occurrence of acromegaly and thyroid cancer still remain controversial, it is particularly important to diagnose the patient early and to rule out thyroid cancer.