Post - prandial rise of microvesicles in peripheral blood of healthy human donors

<p>Abstract</p> <p>Background</p> <p>Microvesicles isolated from body fluids are membrane - enclosed fragments of cell interior which carry information on the status of the organism. It is yet unclear how metabolism affects the number and composition of microvesicles in isolates from the peripheral blood.</p> <p>Aim</p> <p>To study the post - prandial effect on microvesicles in isolates from the peripheral blood of 21 healthy donors, in relation to blood cholesterol and blood glucose concentrations.</p> <p>Results</p> <p>The average number of microvesicles in the isolates increased 5 hours post - prandially by 52%; the increase was statistically significant (p = 0.01) with the power P = 0.68, while the average total blood cholesterol concentration, average low density lipoprotein cholesterol concentration (LDL-C) and average high density lipoprotein cholesterol concentration (HDL-C) all remained within 2% of their fasting values. We found an 11% increase in triglycerides (p = 0.12) and a 6% decrease in blood glucose (p < 0.01, P = 0.74). The post - prandial number of microvesicles negatively correlated with the post - fasting total cholesterol concentration (r = - 0.46, p = 0.035) while the difference in the number of microvesicles in the isolates between post - prandial and post - fasting states negatively correlated with the respective difference in blood glucose concentration (r = - 0.39, p = 0.05).</p> <p>Conclusions</p> <p>In a population of healthy human subjects the number of microvesicles in isolates from peripheral blood increased in the post - prandial state. The increase in the number of microvesicles was affected by the fasting concentration of cholesterol and correlated with the decrease in blood glucose.</p

The meaning of microvesiculation of cell membranes in gastrointestinal cancer : doctoral thesis

Cilj istraživanja: Proučavanje mehanizma vezikulacije, jer su ova znanja još nedovoljna. Želeli smo dokazati da su mikrovezikuli prisutni u izolatima svih tjelesnih tekućina, da je mikrovezikulacija povećana u populaciji bolesnika s rakom probavnih organa, da je u osoba čija plazma uzrokuje jaču interakciju između membrana broj mikrovezikula u krvi manji, te da heparin in vitro povećava privlačne interakcije između membranskih struktura i time inhibira vezikulaciju. Ispitanici i metode: Istraživali smo izolate iz tjelesnih tekućina 80 bolesnika (32 s rakom probavnih organa i 48 s drugim bolestima probavnih organa) i 404 zdrave osobe. Mikrovezikule smo izolirali centrifugiranjem i ispiranjem, brojili protočnim citometrom i slikali scanning elektronskim mikroskopom. Krvnom plazmom prenošenu interakciju između membrana gigantskih fosfolipidnih mjehurića, koje smo stvarali elektroformacijom, mjerili smo kontaktnim kutom između adheziranih mjehurića. Rezultati: Mikrovezikule su prisutne u izolatima svih analiziranih tjelesnih tekućina. Bolesnici s rakom probavnih organa imaju u izlolatima krvi statistički značajno povećanu koncentraciju mikrovezikula (p = 0,0002). Broj mikrovezikula i prosječni kontaktni kut između krvnom plazmom slijepljenih mjehurića u negativnoj su korelaciji (r = –0,50, p = 0,031). Potvrdili smo hipotezu da heparin u terapeutskim koncentracijama pojačava sposobnost plazme da prenosi interakciju privlačenja između membrana (p < 0,01). Zaključci: Mikrovezikulacija je signifikantno pojačana u bolesnika oboljelih od raka probavnih organa. Naši rezultati potvrđuju hipotezu da je interakcija privlačenja između bioloških membrana posredovana plazmatskim sastojcima mogući mehanizam suzbijanja mikrovezikulacije staničnih membrana. Heparin inhibira vezikulaciju time što pojačava interakciju privlačenja između membrana koju prenose sastojci krvne plazme. Taj je učinak mogući mehanizam antikoagulantnog, antimetastatskog i protuupalnog djelovanja heparina.Objectives: The study of mechanism of microvesiculation wich has not been researched yet. We want to show that microvesicles are present in isolates from all body fluids, that microvesiculation is enhanced in patients with gastrointestinal cancer; in subjects whose plasma mediates stronger attractive interaction between membranes, the number of microvesicles in blood isolates is smaller, and that heparin in vitro increases coalescence between membranes and thereby inhibits vesiculation. Patients and Methods: We studied isolates from body fluids of 80 patients (32 with malignant and 48 with non-malignant disease) and 404 healthy subjects. Microvesicles were isolated by centrifugation and washing, counted by flow cytometry and imaged by scanning electron microscopy. Mediated interaction between membranes of giant phospholipid vesicles created by electroformation was assessed by the contact angle between adhered vesicles. Results: Microvesicles were present in isolates from all body fluids considered. The concentration level of micro vesicles in isolates from peripheral blood is significantly higher in patients with cancer of digestive organs (p=0,0002). Number of microvesicles in blood isolates negatively correlates with contact angle between giant phospholipid vesicles adhered due to plasma mediated interaction (r=-0,50, p=0,031). Heparin in therapeutic concentration increases the ability of plasma to mediate attractive interaction between membranes (p<0,01). Conclusions: Microvesiculation is significantly increased in patients with gastrointestinal cancer. Our results are in favour of the hypothesis that attractive interaction mediated by blood plasma is a possible mechanism suppressing microvesiculation of cell membranes. Heparin increases attractive interaction between membranes mediated by blood plasma constituents and thereby suppresses vesiculation. This is a possible mechanism underlying anticoagulant, antimetastatic and antiinflammatory effect of heparin

The meaning of microvesiculation of cell membranes in gastrointestinal cancer : doctoral thesis

Cilj istraživanja: Proučavanje mehanizma vezikulacije, jer su ova znanja još nedovoljna. Želeli smo dokazati da su mikrovezikuli prisutni u izolatima svih tjelesnih tekućina, da je mikrovezikulacija povećana u populaciji bolesnika s rakom probavnih organa, da je u osoba čija plazma uzrokuje jaču interakciju između membrana broj mikrovezikula u krvi manji, te da heparin in vitro povećava privlačne interakcije između membranskih struktura i time inhibira vezikulaciju. Ispitanici i metode: Istraživali smo izolate iz tjelesnih tekućina 80 bolesnika (32 s rakom probavnih organa i 48 s drugim bolestima probavnih organa) i 404 zdrave osobe. Mikrovezikule smo izolirali centrifugiranjem i ispiranjem, brojili protočnim citometrom i slikali scanning elektronskim mikroskopom. Krvnom plazmom prenošenu interakciju između membrana gigantskih fosfolipidnih mjehurića, koje smo stvarali elektroformacijom, mjerili smo kontaktnim kutom između adheziranih mjehurića. Rezultati: Mikrovezikule su prisutne u izolatima svih analiziranih tjelesnih tekućina. Bolesnici s rakom probavnih organa imaju u izlolatima krvi statistički značajno povećanu koncentraciju mikrovezikula (p = 0,0002). Broj mikrovezikula i prosječni kontaktni kut između krvnom plazmom slijepljenih mjehurića u negativnoj su korelaciji (r = –0,50, p = 0,031). Potvrdili smo hipotezu da heparin u terapeutskim koncentracijama pojačava sposobnost plazme da prenosi interakciju privlačenja između membrana (p < 0,01). Zaključci: Mikrovezikulacija je signifikantno pojačana u bolesnika oboljelih od raka probavnih organa. Naši rezultati potvrđuju hipotezu da je interakcija privlačenja između bioloških membrana posredovana plazmatskim sastojcima mogući mehanizam suzbijanja mikrovezikulacije staničnih membrana. Heparin inhibira vezikulaciju time što pojačava interakciju privlačenja između membrana koju prenose sastojci krvne plazme. Taj je učinak mogući mehanizam antikoagulantnog, antimetastatskog i protuupalnog djelovanja heparina.Objectives: The study of mechanism of microvesiculation wich has not been researched yet. We want to show that microvesicles are present in isolates from all body fluids, that microvesiculation is enhanced in patients with gastrointestinal cancer; in subjects whose plasma mediates stronger attractive interaction between membranes, the number of microvesicles in blood isolates is smaller, and that heparin in vitro increases coalescence between membranes and thereby inhibits vesiculation. Patients and Methods: We studied isolates from body fluids of 80 patients (32 with malignant and 48 with non-malignant disease) and 404 healthy subjects. Microvesicles were isolated by centrifugation and washing, counted by flow cytometry and imaged by scanning electron microscopy. Mediated interaction between membranes of giant phospholipid vesicles created by electroformation was assessed by the contact angle between adhered vesicles. Results: Microvesicles were present in isolates from all body fluids considered. The concentration level of micro vesicles in isolates from peripheral blood is significantly higher in patients with cancer of digestive organs (p=0,0002). Number of microvesicles in blood isolates negatively correlates with contact angle between giant phospholipid vesicles adhered due to plasma mediated interaction (r=-0,50, p=0,031). Heparin in therapeutic concentration increases the ability of plasma to mediate attractive interaction between membranes (p<0,01). Conclusions: Microvesiculation is significantly increased in patients with gastrointestinal cancer. Our results are in favour of the hypothesis that attractive interaction mediated by blood plasma is a possible mechanism suppressing microvesiculation of cell membranes. Heparin increases attractive interaction between membranes mediated by blood plasma constituents and thereby suppresses vesiculation. This is a possible mechanism underlying anticoagulant, antimetastatic and antiinflammatory effect of heparin

peer review: awaiting peer review]

Background: The aim of the current study was to assess the patients with COVID-19 and the impact of vitamin D supplementation on the course of COVID-19. Methods: This prospective cohort study included patients hospitalized due to COVID-19 between December 2020 and December 2021. Patients\u27 demographic, clinical, and laboratory parameters were analysed. Results: 301 participants were enrolled in the study. 46 (15,3%) had moderate, and 162 (53,8%) had severe COVID-19. 14 (4,7%) patients died, and 30 (10,0%) were admitted to the ICU due to disease worsening. The majority needed oxygen therapy (n=22474,4%). Average vitamin 25(OH)D3 levels were below optimal at the admittance, and vitamin D deficiency was detected in 205 individuals. More male patients were suffering from vitamin D deficiency. Patients with the more severe disease showed lower levels of vitamin 25(OH)D3 in their blood. The most severe group of patients had more symptoms that lasted significantly longer with progressing disease severity. This group of patients also suffered from more deaths, ICU admissions, and treatments with dexamethasone, remdesivir, and oxygen. Conclusion: Patients with the severe course of COVID-19 were shown to have increased inflammatory parameters, increased mortality, and higher incidence of vitamin D deficiency. The results suggest that the vitamin D deficiency might represent a significant risk factor for a severe course of COVID-19

Effect of shear stress in the flow through the sampling needle on concentration of nanovesicles isolated from blood

During harvesting of nanovesicles (NVs) from blood, blood cells and other particles in blood are exposed to mechanical forces which may cause activation of platelets, changes of membrane properties, cell deformation and shedding of membrane fragments. We report on the effect of shear forces imposed upon blood samples during the harvesting process, on the concentration of membrane nanovesicles in isolates from blood. Mathematical models of blood flow through the needle during sampling with vacuumtubes and with free flow were constructed, starting from the Navier-Stokes formalism. Blood was modeled as a Newtonian fluid. Work of the shear stress was calculated. In experiments, nanovesicles were isolated by repeated centrifugation (up to 17,570×g) and washing, and counted by flow cytometry. It was found that the concentration of nanovesicles in the isolates positively corresponded with the work by the shear forces in the flow of the sample through the needle. We have enhanced the effect of the shear forces by shaking the samples prior to isolation with glass beads. Imaging of isolates by scanning electron microscopy revealed closed globular structures of a similar size and shape as those obtained from unshaken plasma by repetitive centrifugation and washing. Furthermore, the sizes and shapes of NVs obtained by shaking erythrocytes corresponded to those isolated from shaken platelet-rich plasma and from unshaken platelet rich plasma, and not to those induced in erythrocytes by exogenously added amphiphiles. These results are in favor of the hypothesis that a significant pool of nanovesicles in blood isolates is created during their harvesting. The identity, shape, size and composition of NVs in isolates strongly depend on the technology of their harvesting.</p

A prospective phase II study evaluating intraoperative electrochemotherapy of hepatocellular carcinoma

The aim of this clinical study was to investigate the effectiveness and long-term safety of electrochemotherapy as an emerging treatment for HCC in patients not suitable for other treatment options. A prospective phase II clinical study was conducted in patients with primary HCC who were not suitable for other treatment options according to the Barcelona Clinic Liver Cancer classification. A total of 24 patients with 32 tumors were treated by electrochemotherapy. The procedure was effective, feasible, and safe with some procedure-related side effects. The responses of the 32 treated nodules were: 84.4% complete response (CR), 12.5% partial response (PR), and 3.1% stable disease (SD). The treatment was equally effective for nodules located centrally and peripherally. Electrochemotherapy provided a durable response with local tumor control over 50 months of observation in 78.0% of nodules. The patient responses were: 79.2% CR and 16.6% PR. The median progression-free survival was 12 months (range 2.7–50), and the overall survival over 5 years of observation was 72.0%. This prospective phase II clinical study showed that electrochemotherapy was an effective, feasible, and safe option for treating HCC in patients not suitable for other treatment options

Slovenska priporočila za obravnavo odraslih bolnikov s kronično odpovedjo prebavil

no abstractSlovenska priporočila za obravnavo bolnikov z kronično odpovedjo prebavil so povzeta so po smernicah Evropskega združenja za klinično prehrano in metabolizem (angl. ESPEN; European Society for Clinical Nutrition and Metabolism) in prilagojena slovenskim izkušnjah zdravljenja odpovedi prebavil. Pretežni del bolnikov z odpovedjo prebavil predstavljajo bolniki s sindromom kratkega črevesa (SKČ), zato je poudarek priporočil na diagnostiki, obravnavi in zdravljenju bolnikov s SKČ. Namen priporočil je vzpostavitev bolj učinkovite prepoznave in obravnave bolnikov z odpovedjo ter vzpostavitvi temeljnih strokovnih izhodišč za zdravljenje teh bolnikov v Sloveniji. Dejavnost zdravljenja kronične odpovedi prebavil z parenteralno prehrano na domu pri odrasli pacientih je bila v Sloveniji formalno vzpostavljena leta 2008, v 13 letih smo zdravili več kot 230 pacientov, v začetku leta 2021 je v 2 centrih (OI Ljubljana, UKC Ljubljana) v zdravljenje vključeno 95 odraslih bolnikov. Pred 6 leti Smo paciente v programu zdravljenja odpovedi prebavil v okviru OI LjubljanA vključili v evropski register premljanja bolnikov na Parenteralni prehrani na domu (PPD), v okviru ESPEN