Detection of acute gastrointestinal bleeding by means of technetium-99m in vivo labelled red blood cells

BACKGROUND: Prognosis of gastrointestinal (GI) bleeding depends on the timely [3] and accurate [8, 18] detection of the source of bleeding and sequential surgical or endoscopy therapy. Scintigraphy with red blood cells (RBCs) in vivo labelled by means of technetium-99m hastened detection of source of GI bleeding and improved management of the particular disease. Gastrointestinal endoscopy is the method of choice for the diagnostics of bleeding from upper tract and large bowel. For diagnostics of bleeding from the small bowel we can use scintigraphy with in vivo labelled autological red blood cells if pushenteroscopy, intra-operative enteroscopy or angiography are not available. MATERIAL AND METHODS: 31 patients (13 men, 18 women, aged 20-91, mean 56 years) underwent this investigation from 1998 till 2001 at the Department of Nuclear Medicine. All patients had melaena or enterorrhagia associated with acute anaemia. Gastroscopy, colonoscopy, enteroclysis or X-ray angiography did not detect the source of bleeding. RESULTS: Twenty-one patients had positive scintigraphy with in vivo labelled RBCs - 9 patients were already positive on dynamic scintigraphy, and 12 patients were positive on static images. Scintigraphy with in vivo labelled RBCs was negative in 10 patients. GI bleeding stopped spontaneously in these 10 patients with negative scintigraphy. These patients did not undergo intra- operative enteroscopy or surgery. The final diagnosis of the 21 patients with positive scintigraphy was determined in 16 patients by push-enteroscopy (6 patients), intra-operative enteroscopy (6 patients) or by surgery (4 patients). Of these 16 patients the correct place of bleeding was determined by scintigraphy with labelled RBCs in 11 (69%) patients. Final diagnoses of our 16 patients with positive scintigraphy with autological labelled RBCs were: bleeding small bowel arteriovenous malformation (6 patients), uraemic enteritis with bleeding erosions in ileum and jejunum (2 patients), Osler-Rendu- Weber disease (1 patient), pseudocyst of the pancreas with bleeding vessel communicating to the transverse colon (1 patient), bleeding submucose varix in jejunum (1 patient), carcinoid of the ileum (1 patient), bleeding from the ileosigmoideoanastomosis six days after hemicolectomy for Crohn´s disease (1 patient), bleeding from an ulcer close to the papilla of Vater (1 patient), bleeding from ulcer at jejunum after revious NSAIDs treatment (1 patient), bleeding inflammatory polyp at ileotransversoanastomosis (1 patient). GI bleeding stopped spontaneously in 5 patients with positive scintigraphy. Therefore these patients did not undergo intraoperative enteroscopy or surgery and we could not determine the final diagnosis. CONCLUSIONS: Scintigraphy with RBCs in vivo labelled technetium- 99m hastened detection of the source of GI bleeding and improved management of the source of GI bleeding and improved management of disease

Eye Tracking Using Nonverbal Tasks Could Contribute to Diagnostics of Developmental Dyslexia and Developmental Language Disorder

There are not many studies dealing with a comparison of the eye movements of individuals with dyslexia and developmental language disorder (DLD). The aim of this study is to compare the eye movements in the two most common language disorders, dyslexia and DLD and to consider their contribution to diagnostics. In the research the oculomotor test was administered to 60 children with the clinical diagnosis of dyslexia or DLD and 58 typically developing children (controls). The test included a prosaccadic task, antisaccadic task and a nonverbal sequential task with self-regulation of the pace. Controls could be singled out from other two clinical groups by means of the oculomotor imaging. Both of the clinical groups in comparison with the controls were characterized by worse overall performance. Through the employment of the oculomotor it was possible to differentiate between both of the clinical groups. The dyslexics had an overall worse oculomotor performance than the DLD group. The results of the study show that the oculomotor test has the potential to contribute to diagnostics of dyslexia and DLD and the screening of these disorders at pre-school age

Uporaba voltmetrije za određivanje tiola i metalotioneina male molekularne mase u krvi svinje (Sus scrofa domestica)

Metallothioneins (MT) play a key role in maintaining the homeostasis of essential metals and in protecting of cells against metal toxicity as well as cell oxidative damaging. The aim of this work is to propose a new approach for processing a biological sample for analysis of thiols including metallothioneins. Moreover, the proposed procedure is tested on quantification of MT and total thiol content in blood serum of pig (Sus scrofa domestica), which has not been previously been performed. The blood serum (10 ml) was collected and transferred to 0.2 M phosphate buffer (990 ml). The sample (100 × diluted) was placed in a thermomixer, where heat denaturation of most of the proteins proceeded. The processed blood serum sample was electrochemically measured to determine total content of thiols (cysteine, glutathione, metallothionein and other low molecular thermostable thiols) and content of MT. The average level of the thiols and MT were estimated as 165 ± 20 mM and 5.2 ± 0.6 mM, respectively.Metalotioneini (MT) igraju ključnu ulogu u održavanju homeostaze esencijalnih metala i u zaštiti od toksičnih metala te od oštećivanja stanice oksidacijom. Cilj ovog rada je predložiti novi pristup obradi bioloških uzoraka za analizu tiola, uključujući metalotioneine. Osim toga, predloženi postupak se testira pri kvantifikaciji MT i ukupnog sadržaja tiola u krvnom serumu svinje (Sus scrofa domestica), što se dosad nije radilo. Prikupljan je krvni serum (10 ml) te prebacivan u 0.2 M fosfatni pufer (990 ml). Uzorak (100 × razrijeđen) je stavljen u termomikser gdje se nastavila toplinska denaturacija većine proteina. Obrađeni uzorak seruma je elektrokemijski izmjeren da bi se odredio ukupni sadržaj tiola (cistein, glutation, metalotionein i drugi termostabilni tioli male molekularne mase) te sadržaj MT. Prosječna razina tiola i MT su procijenjeni na 165 ± 20 mM, odnosno 5.2 ± 0.6 mM

Detecting local adaptation in widespread grassland species – the importance of scale and local plant community

1 Adaptation of plant populations to local environments has been shown in many species but local adaptation is not always apparent and spatial scales of differentiation are not well known. In a reciprocal transplant experiment we tested whether: (i) three widespread grassland species are locally adapted at a European scale; (ii) detection of local adaptation depends on competition with the local plant community; and (iii) local differentiation between neighbouring populations from contrasting habitats can be stronger than differentiation at a European scale.2 Seeds of Holcus lanatus, Lotus corniculatus and Plantago lanceolata from a Swiss, Czech and UK population were sown in a reciprocal transplant experiment at fields that exhibit environmental conditions similar to the source sites. Seedling emergence, survival, growth and reproduction were recorded for two consecutive years.3 The effect of competition was tested by comparing individuals in weeded monocultures with plants sown together with species from the local grassland community. To compare large-scale vs. small-scale differentiation, a neighbouring population from a contrasting habitat (wet-dry contrast) was compared with the 'home' and 'foreign' populations.4 In P. lanceolata and H. lanatus, a significant home-site advantage was detected in fitness-related traits, thus indicating local adaptation. In L. corniculatus, an overall superiority of one provenance was found.5 The detection of local adaptation depended on competition with the local plant community. In the absence of competition the home-site advantage was underestimated in P. lanceolata and overestimated in H. lanatus.6 A significant population differentiation between contrasting local habitats was found. In some traits, this small-scale was greater than large-scale differentiation between countries.7 Our results indicate that local adaptation in real plant communities cannot necessarily be predicted from plants grown in weeded monocultures and that tests on the relationship between fitness and geographical distance have to account for habitat-dependent small-scale differentiation. Considering the strong small-scale differentiation, a local provenance from a different habitat may not be the best choice in ecological restoration if distant populations from a more similar habitat are available

Development of submicromolar 17β-HSD10 inhibitors and their in vitro and in vivo evaluation

Funding: This study was supported by the Ministry of Education, Youth, and Sports of the Czech Republic (project ESF no. CZ.02.1.01/0.0/0.0/18_069/0010054), by the University of Hradec Kralove (Faculty of Science, no. SV2103‐2022), by Charles University, Prague, Czech Republic (project Cooperatio, research area Neurosciences), by the project MH CZ-DRO VFN64165, and by MH CZ - DRO (UHHK, 00179906), by the Ministry of Defence of the Czech Republic (Faculty of Military Health Sciences Hradec Kralove) under the grant entitled the “Long-term organization development plan - Medical Aspects of Weapons of Mass Destruction”, and by the RS MacDonald Charitable Trust and Rosetrees Trust.17β-hydroxysteroid dehydrogenase type 10 (17β-HSD10) is a multifunctional mitochondrial enzyme and putative drug target for the treatment of various pathologies including Alzheimer's disease or some types of hormone-dependent cancer. In this study, a series of new benzothiazolylurea-based inhibitors were developed based on the structure-activity relationship (SAR) study of previously published compounds and predictions of their physico-chemical properties. This led to the identification of several submicromolar inhibitors (IC50 ∼0.3 μM), the most potent compounds within the benzothiazolylurea class known to date. The positive interaction with 17β-HSD10 was further confirmed by differential scanning fluorimetry and the best molecules were found to be cell penetrable. In addition, the best compounds weren't found to have additional effects for mitochondrial off-targets and cytotoxic or neurotoxic effects. The two most potent inhibitors 9 and 11 were selected for in vivo pharmacokinetic study after intravenous and peroral administration. Although the pharmacokinetic results were not fully conclusive, it seemed that compound 9 was bioavailable after peroral administration and could penetrate into the brain (brain-plasma ratio 0.56).Peer reviewe

Biotic homogenization destabilizes ecosystem functioning by decreasing spatial asynchrony

Our planet is facing significant changes of biodiversity across spatial scales. Although the negative effects of local biodiversity (α diversity) loss on ecosystem stability are well documented, the consequences of biodiversity changes at larger spatial scales, in particular biotic homogenization, that is, reduced species turnover across space (β diversity), remain poorly known. Using data from 39 grassland biodiversity experiments, we examine the effects of β diversity on the stability of simulated landscapes while controlling for potentially confounding biotic and abiotic factors. Our results show that higher β diversity generates more asynchronous dynamics among local communities and thereby contributes to the stability of ecosystem productivity at larger spatial scales. We further quantify the relative contributions of α and β diversity to ecosystem stability and find a relatively stronger effect of α diversity, possibly due to the limited spatial scale of our experiments. The stabilizing effects of both α and β diversity lead to a positive diversity–stability relationship at the landscape scale. Our findings demonstrate the destabilizing effect of biotic homogenization and suggest that biodiversity should be conserved at multiple spatial scales to maintain the stability of ecosystem functions and services

Effects of plant diversity on productivity strengthen over time due to trait-dependent shifts in species overyielding

Plant diversity effects on community productivity often increase over time. Whether the strengthening of diversity effects is caused by temporal shifts in species-level overyielding (i.e., higher species-level productivity in diverse communities compared with monocultures) remains unclear. Here, using data from 65 grassland and forest biodiversity experiments, we show that the temporal strength of diversity effects at the community scale is underpinned by temporal changes in the species that yield. These temporal trends of species-level overyielding are shaped by plant ecological strategies, which can be quantitatively delimited by functional traits. In grasslands, the temporal strengthening of biodiversity effects on community productivity was associated with increasing biomass overyielding of resource-conservative species increasing over time, and with overyielding of species characterized by fast resource acquisition either decreasing or increasing. In forests, temporal trends in species overyielding differ when considering above- versus belowground resource acquisition strategies. Overyielding in stem growth decreased for species with high light capture capacity but increased for those with high soil resource acquisition capacity. Our results imply that a diversity of species with different, and potentially complementary, ecological strategies is beneficial for maintaining community productivity over time in both grassland and forest ecosystems

Global patterns and drivers of alpine plant species richness

Aim Alpine ecosystems differ in area, macroenvironment and biogeographical history across the Earth, but the relationship between these factors and plant species richness is still unexplored. Here, we assess the global patterns of plant species richness in alpine ecosystems and their association with environmental, geographical and historical factors at regional and community scales. Location Global. Time period Data collected between 1923 and 2019. Major taxa studied Vascular plants. Methods We used a dataset representative of global alpine vegetation, consisting of 8,928 plots sampled within 26 ecoregions and six biogeographical realms, to estimate regional richness using sample‐based rarefaction and extrapolation. Then, we evaluated latitudinal patterns of regional and community richness with generalized additive models. Using environmental, geographical and historical predictors from global raster layers, we modelled regional and community richness in a mixed‐effect modelling framework. Results The latitudinal pattern of regional richness peaked around the equator and at mid‐latitudes, in response to current and past alpine area, isolation and the variation in soil pH among regions. At the community level, species richness peaked at mid‐latitudes of the Northern Hemisphere, despite a considerable within‐region variation. Community richness was related to macroclimate and historical predictors, with strong effects of other spatially structured factors. Main conclusions In contrast to the well‐known latitudinal diversity gradient, the alpine plant species richness of some temperate regions in Eurasia was comparable to that of hyperdiverse tropical ecosystems, such as the páramo. The species richness of these putative hotspot regions is explained mainly by the extent of alpine area and their glacial history, whereas community richness depends on local environmental factors. Our results highlight hotspots of species richness at mid‐latitudes, indicating that the diversity of alpine plants is linked to regional idiosyncrasies and to the historical prevalence of alpine ecosystems, rather than current macroclimatic gradients