Browsing by Author "Zolovs, M."

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    Distinct B cell profiles characterise healthy weight and obesity pre- and post-bariatric surgery
    (2023-10) Šlisere, B.; Arisova, M.; Aizbalte, O.; Salmiņa, M. M.; Zolovs, M.; Levenšteins, M.; Mukāns, M.; Troickis, I.; Meija, L.; Lejnieks, A.; Bīlande, G.; Rosser, E. C.; Oļeiņika, K.; Department of Doctoral Studies; Department of Human Physiology and Biochemistry; Institute of Public Health; Statistics Unit; Department of Internal Diseases
    BACKGROUND/OBJECTIVES: Obesity-associated metabolic dysfunction and inflammation can be ameliorated by bariatric surgery. While obesity is also linked to impaired B cell activation, differentiation, and persistence in response to infection and vaccination little is known about post-operative immune B cell compartment and to what extent dysregulation in B cell pathways can be reversed. To bridge this gap in knowledge, we carried out in-depth evaluation of B cell composition in individuals with obesity prior to and following bariatric surgery compared to lean controls. SUBJECTS/METHODS: We recruited individuals with obesity (BMI at least 35 kg/m 2) before bariatric surgery (n = 21) and followed them up 6 months post-operatively (n = 17). As controls we recruited age- and sex-matched lean (BMI < 25) individuals (n = 18). We carried out comprehensive immunophenotyping of peripheral blood B cells as well as interrogated their association with inflammatory and metabolic parameters. RESULTS: In obesity the balance of antigen-inexperienced and memory B cells in the peripheral blood is altered, with an expansion of naïve and a reduction in total memory B cells. 6 months following bariatric surgery this balance is restored. However, post-operative patients are uniquely characterised by an increase in B cell subsets associated with chronic inflammation - CD11c +CXCR5 -IgD -CD27 - double negative 2 (DN2) B cells and CD27 +CD38 ++ plasmablasts. Correlations between B cells subsets, inflammatory and metabolic parameters were distinct in lean people and individuals with obesity pre- and post-bariatric surgery. CONCLUSIONS: Bariatric surgery patients display a unique B cell profile 6 months post-operatively; this bears minimal resemblance to that of pre-operative patients and only partially overlaps with that of lean controls. Post-operative differences in the B cell compartment compared to lean controls are detected despite global amelioration of inflammation and restoration of metabolic health. Collectively, this indicates that bariatric surgery creates a specific immunometabolic state with potential implications for health outcomes.
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    The first comprehensive population size estimations for the highly endangered largest diving beetle Dytiscus latissimus in Europe
    (2023-06-15) Balalaikins, M.; Schmidt, G.; Aksjuta, K.; Hendrich, L.; Kairišs, K.; Sokolovskis, K.; Valainis, U.; Zolovs, M.; Nitcis, M.; Statistics Unit
    Dytiscus latissimus (Coleoptera Dytiscidae) is an endangered diving beetle throughout its range. It is one of the two species of Dytiscidae listed in Annex II of the Habitats Directive, IUCN red list and in many national level legislations and therefore strictly protected. The conservation of endangered species first of all requires an assessment of their population size. Until now, a method has not been developed for estimating the size of D. latissimus populations. The article summarizes the results of two studies carried out independently in Germany and Latvia. Both studies were carried out in one water body used recapture method but with a different spatial placement of traps, which, according to our data, is an important factor in population estimation. We evaluated Jolly-Seber and Schnabel approaches of estimating aquatic beetle's populations and found that confidence intervals obtained by different methods in our research do not differ significantly, but combination of both models provide the most accurate estimates of population dynamics. As part of the study, we concluded that the populations of Dytiscus latissimus are relatively closed, so we accept that the Schnabel estimate shows more accurate data. By fixing the places of capture of each individual, it was found that females live mainly locally, and males actively move within the water body. This aspect indicates the advantage of the spatial placement of traps compared to the use of transects. The results of our study show a significantly higher number of both captured and recaptured males Such a sex ratio may indicate both a greater activity of males and differences in the sex ratio in the population. The study confirmed that environmental changes, such as the water level in a water body, can also significantly affect the result of a population assessment. In the frame of D. latissimus monitoring, to obtain an objective estimation of the species population size we recommend using four traps for each 100 m of water body shoreline with 4–8 censuses, dependently on the recapture rate.