Automation of Operation Control of the Human Centrifuge

Human centrifuge is a motion platform used to artificially achieve transient and sustained G-load intended for physiological pilot training under controlled conditions. This paper presents the successful modernization and upgrade of the control system of the human centrifuge. Due to the need for system redundancy, in addition to the new automatic control system, the previously used manual control system had to be maintained, which is provided by the usage of a switch selector. Human centrifuge speed and positioning control algorithms are based on the implementation of a digital PI and P controller

The application of benthic diatoms in water quality assessment (Mlava River, Serbia)

The main objective of this study was to assess the ecological status of the Mlava River based on epilithic diatoms and to test the use of diatom indices as a tool for estimating the quality of flowing waters in Serbia. Quantitative analysis showed that in April Achnanthidium minutissimum was dominant at each site, except at the fi fth site, where Amphora pediculus was dominant. In July and September, Achnanthidium minutissimum, Achnanthidium pyrenaicum, Amphora pediculus, Denticula tenuis, Diatoma vulgaris, Gomphonema elegantissimum, Cocconeis pseudolineata and Cocconeis placentula var. lineata dominated. Detrended correspondence analysis (DCA) was used to detect the major patterns of variation in species composition. The first DCA axis summarizes the distribution of the diatom community, mainly through temperature, conductivity, oxygen and water hardness gradient. The second DCA axis was weakly correlated with few variables. Based on the average values of the pollution sensitivity index (IPS), commission for economical community metric (CEE) and biological diatom index (IBD), the water of the Mlava River belonged to water class I during all three seasons. Values of the diatom-based eutrophication/pollution index (EPI-D) indicated class II water quality. According to calculated trophic diatom index (TDI) values, water of the Mlava River was characterized by intermediate nutrient concentrations during three seasons. Principal components analysis was used to represent the correlation between diatom indices, and the highest correlation among the selected diatom indices is seen between EPI-D, IPS and IBD

En route to dynamic life processes by SNARE-mediated fusion of polymer and hybrid membranes

A variety of artificial cells springs from the functionalization of liposomes with proteins. However, these models suffer from low durability without repair and replenishment mechanisms, which can be partly addressed by replacing the lipids with polymers. Yet natural membranes are also dynamically remodeled in multiple cellular processes. Here, we show that synthetic amphiphile membranes also undergo fusion, mediated by the protein machinery for synaptic secretion. We integrated fusogenic SNAREs in polymer and hybrid vesicles and observed efficient membrane and content mixing. We determined bending rigidity and pore edge tension as key parameters for fusion and described its plausible progression through cryo-EM snapshots. These findings demonstrate that dynamic membrane phenomena can be reconstituted in synthetic materials, thereby providing new tools for the assembly of synthetic protocells

Bilijarna funkcija u radnika profesionalno izloženih aluminijskoj prašini i dimu

This study investigated billiary secretory function in workers occupationally exposed to aluminium dust and fumes. It included a group of 34 male workers aged (44.1±7.8) years and exposed up to 4.6 mg m-3 of aluminium dust and fumes in workplace air for (21.6±2.5) years, and a group of 30 unexposed control male workers. Serum and urine aluminium levels were measured in both groups before and after chelating treatment with 1 g deferoxamine by intramuscular injection. Billiary function was assessed by measuring gamma-glutamyl transpeptidase, alkaline phosphatase, 5-nucleotidase, cholesterol and its fractions, total and indirect bilirubin, and bile acids. We then analysed the relationship between Al exposure and billiary function. In the exposed group mean serum aluminium was significantly higher [(4.91±3.86) µg L-1] than in controls. The same was true for urine Al before [(1.57±1.93) µg L-1] and after deferoxamine [(11.51±14.97) µg L-1]. Total and indirect bilirubin and alkaline phosphatase were significantly higher in the exposed than in control workers, and they correlated with urine Al after the chelating treatment. Our findings suggest that chronic occupational exposure to aluminium dust and fumes leads to a significant body retention of aluminium. The impaired biliary secretion in the exposed workers manifested itself in subclinical signs of cholestasis.Eksperimentalna istraživanja na životinjama pokazuju da kronična izloženost aluminiju može izazvati smanjen prijenos organskih aniona preko žučnih kanalića, što ima za posljedicu poremećaje sekrecije žuči i kolestazu. Učinci kronične izloženosti aluminiju na bilijarnu funkciju u ljudi do sada nisu istraživani. Procjenjivali smo učinke na bilijarnu funkciju radnika koji su profesionalno izloženi prašini i dimu aluminija. U izloženoj skupini bila su 34 muškarca, životne dobi (44,1±7,8) godina koji su tijekom (21,6±2,5) godina bili izloženi razini do 4,6 mg m-3 prašine i dima aluminija. Kontrolna skupina sastojala se od 30 neizloženih radnika. Vrijednosti aluminija određene su u serumu i mokraći u obje skupine prije i nakon davanja kelatirajućeg spoja (deferoksamin u dozi od 1 g im.). Za procjenu bilijarne funkcije rabljeni su ovi pokazatelji: γ-glutamil transpeptidaza, alkalna fosfataza, 5-nukleozidaza, kolesterol, ukupni i indirektni bilirubin te žučne kiseline. Analizirana je korelacija između izloženosti aluminiju i bilijarne funkcije. Srednja vrijednost Al u serumu izloženih radnika [(4,91±3,86) µg L-1], kao i koncentracije Al u mokraći prije [(1,57±1,93) µg L-1] i nakon primjene kelatirajućeg spoja [(11,5±15,0) µg L-1] bile su statistički značajno više u odnosu na vrijednosti u kontrolnih ispitanika. Vrijednosti ukupnog i indirektnoog bilirubina te alkalne fosfataze bile su statistički značajno više u izloženih radnika i pozitivno su korelirale s ukupnim Al izlučenim mokraćom nakon primjene kelatora. Može se zaključiti da kronična profesionalna izloženost prašini i dimu aluminija dovodi do tjelesnog opterećenja aluminijem i poremećaja bilijarne funkcije, što se odražava supkliničkim znakovima kolestaze

Ocjena radne sposobnosti pacijenta s Wilsonovom bolesti - prikaz bolesnika

Wilson’s disease (WD) is a rare, progressive autosomal recessive disorder characterised by impaired transport and excessive accumulation of copper in the liver, brain, and other tissues. The disease is diagnosed based on clinical manifestations and screening tests results. Work ability assessment of patients with WD is based on the analysis of liver, kidney, neurological, and cognitive impairments, and takes into account patient’s level of education. This article presents a case with a 48-year-old male patient, who was admitted for work ability assessment due to polymorphic symptoms. The patient had been working as a salesman for 28 years. A detailed interview and examination by occupational health and other medical specialists revealed that the patient had been suffering from Wilson’s disease from the age of 13, and had now developed hepatic manifestations (compensated liver cirrhosis with portal hypertension), neurological manifestations (dystonia, dysarthria, muscle weakness, vertigo), and psychiatric manifestations (depression, insomnia, cognitive impairment) of the disease, including problems partially caused by long-lasting treatment with copper chelating agents (neurological and haematological manifestations). There were no ocular manifestations of Wilson’s disease (Kayser-Fleischer rings or sunflower cataract). The patient was assessed as having drastically diminished general work ability, dominantly due to neurological and psychiatric impairments caused by Wilson’s disease.Wilsonova je bolest rijetka, progresivna autosomno recesivna bolest karakterizirana poremećajem transporta bakra i posljedičnim prekomjernim nakupljanjem bakra u jetri, mozgu i drugim tkivima i organima. Dijagnoza bolesti postavlja se na osnovi kliničkih manifestacija bolesti i nalaza laboratorijskih ispitivanja. Ocjena radne sposobnosti pacijenata s Wilsonovom bolesti zasniva se na analizi postojanja oštećenja i stupnja oštećenja hepatičkih, neuroloških, bubrežnih i kognitivnih funkcija, kao i na analizi stupnja obrazovanja pacijenata. Prikazan je slučaj D. M., 48-godišnjeg pacijenta, koji je primljen zbog polimorfnih tegoba na bolničko ispitivanje radi ocjene radne sposobnosti. Pacijent je radio kao prodavač posljednjih 28 godina. Nakon detaljne anamneze i pregleda koje su obavili specijalisti medicine rada i drugi specijalisti utvrđeno je da pacijent boluje od Wilsonove bolesti od 13. godine života i da u ovom trenutku ima izražene hepatične manifestacije (kompenzirana ciroza jetre s portalnom hipertenzijom), neurološke manifestacije (distonija, dizartrija, mišićna slabost, vrtoglavica) i psihijatrijske manifestacije (depresija, nesanica, kognitivno oštećenje) Wilsonove bolesti, kao i da su prisutne tegobe djelomično uzrokovane dugotrajnom upotrebom kelatne terapije (neurološki i hematološki poremećaji). Nisu uočene karakteristične očne promjene Wilsonove bolesti (Kayser-Fleischerov prsten, katarakta u obliku suncokreta). Ocjenom radne sposobnosti utvrđeno je da pacijent ima drastično smanjenu radnu sposobnost pretežno zbog neuroloških i psihičkih poremećaja u sklopu Wilsonove bolesti

Enrichment of Cxcl12 promoter with TET2: a possible link between promoter demethylation and enhanced gene expression in the absence of PARP-1

Previously, we described the link between C-X-C motif chemokine 12 (Cxcl12) gene induction and DNA hypomethylation in the absence of poly(ADP-ribose) polymerase 1 (PARP-1). We have now firmly established that demethylation is the primary cause of gene induction on the basis of Cxcl12 gene upregulation upon treatment with the demethylating agent 5-azacytidine (5-aza). Since the demethylation state of Cxcl12 is favored by PARP-1 absence, we investigated the presence of ten-eleven translocation (TET) proteins on the Cxcl12 promoter in order to corroborate the relationship between the demethylation process and increased gene expression that occurs in the absence of PARP-1. Analysis was performed on the promoter region within CpG islands of Cxcl12 from control mouse embryonic fibroblasts (NIH3T3) and PARP-1 knock-out mouse embryonic fibroblasts (PARP1-/-). The lack of PARP-1 increased the abundance of TET2 on the Cxcl12 promoter, suggesting that TET-mediated demethylation provoked by the absence of PARP-1 could account for the observed increased expression of this chemokine. Deciphering the regulation of DNA (de)methylation factors that control Cxcl12 expression may provide an additional therapeutic approach in pharmacological interventions where gene switching on or off based on targeted stimulation or inhibition is necessary

Enrichment of Cxcl12 promoter with TET2: a possible link between promoter demethylation and enhanced gene expression in the absence of PARP-1

Previously, we described the link between C-X-C motif chemokine 12 (Cxcl12) gene induction and DNA hypomethylation in the absence of poly(ADP-ribose) polymerase 1 (PARP-1). We have now firmly established that demethylation is the primary cause of gene induction on the basis of Cxcl12 gene upregulation upon treatment with the demethylating agent 5-azacytidine (5-aza). Since the demethylation state of Cxcl12 is favored by PARP-1 absence, we investigated the presence of ten-eleven translocation (TET) proteins on the Cxcl12 promoter in order to corroborate the relationship between the demethylation process and increased gene expression that occurs in the absence of PARP-1. Analysis was performed on the promoter region within CpG islands of Cxcl12 from control mouse embryonic fibroblasts (NIH3T3) and PARP-1 knock-out mouse embryonic fibroblasts (PARP1-/-). The lack of PARP-1 increased the abundance of TET2 on the Cxcl12 promoter, suggesting that TET-mediated demethylation provoked by the absence of PARP-1 could account for the observed increased expression of this chemokine. Deciphering the regulation of DNA (de)methylation factors that control Cxcl12 expression may provide an additional therapeutic approach in pharmacological interventions where gene switching on or off based on targeted stimulation or inhibition is necessary

Transdifferentiation of pancreatic alpha to beta cells using Epi-CRISPR directed DNA methylation

Introduction: Since diabetes is characterized by impaired ability of pancreatic betacells to respond and/or produce insulin, new approaches for renewal and replacement of deficient beta-cells are indispensable. The aim of this study is direct pancreatic alpha- to beta-cells transdifferentiation by using a new synthetic epigenetic tool, Epi-CRISPR system. Using Epi-CRISPR system we aim to introduce targeted DNA methylation and subsequent repression of genes responsible for maintaining alpha-cell identity. Methods: AlphaTC1-6 cells (α-cells) were transiently transfected with dCas9-Dnmt3a- Dnmt3L constructs and one or four different vectors containing guide RNA components for specific targeting the promoter region of aristaless-related homeobox gene (Arx). The success of α-cells transdifferentiation into insulinproducing cells was evaluated by measuring Arx and insulin mRNA level, amount of secreted insulin and by immunostaining of insulin/glucagon in the cells. Results: We observed Arx transcriptional repression in α-cell transfected with Epi- CRISPR construct that targets the Arx gene promoter inducing subsequent methylation. At fifth day post-transfection the expression of Arx was decreased in α- cells followed by consequent increase in insulin (mRNA and protein level). At the same time, the glucagon levels remained unchanged. At twelfth day posttransfection the transfected cells start to lose glucagon while still secreting insulin. Conclusion: This study is near to confirm Epi-CRISPR system functionality and to verify the concept of cell transdifferentiation through silencing of genes responsible for maintaining cell phenotype. The obtained results will be valuable for later Epi- CRISPRs use in mouse in vivo models of diabetes and eventually as a future therapy for diabetes attenuation in humans.Brajušković G, Đorđević A, editors. CoMBoS. 1st Congress of Molecular Biologists of Serbia; 2017 Sep 20-21; Belgrade, Serbia. Belgrade: University of Belgrade, Faculty of Biology; 2017. p. 73