Extracellular Matrix protein gelatin provides higher expansion, reduces size heterogeneity, and maintains cell stiffness in a long-term culture of mesenchymal stem cells.

Extracellular matrices (ECM) present in our tissues play a significant role in maintaining tissue homeostasis through various physical and chemical cues such as topology, stiffness, and secretion of biochemicals. They are known to influence the behaviour of resident stem cells. It is also known that ECM type and coating density on cell culture plates strongly influence in vitro cellular behaviour. However, the influence of ECM protein coating on long term mesenchymal stem cell expansion has not been studied yet. To address this gap, we cultured bone-marrow derived hMSCs for multiple passages on the tissue culture plastic plates coated with 25 μg/ml of various ECM proteins. We found that cells on plates coated with ECM proteins had much higher proliferation compared to the regular tissue culture plates. Further, gelatin coated plates helped the cells to grow faster compared to collagen, fibronectin, and laminin coated plates. Additionally, the use of Gelatin showed less size heterogeneity among the cells when expanded from passages P3 to P9. Gelatin also helped in maintaining cellular stiffness which was not observed across other ECM proteins. In summary, in this research, we have shown that gelatin which is the least expensive compared to other ECM proteins provides a better platform for mesenchymal stem cell expansion.

A systematic review and meta-analysis of HIV associated neurocognitive disorders (HAND) among people with HIV in Ethiopia

Background Ethiopia, being in the Sub Saharan region of Africa, is one of the countries with a substantial burden of HIV infection. Because of the high burden of HIV and poor health care settings, HAND is prevalent as demonstrated in various cross-sectional studies. However, no review has been conducted to report the consolidated magnitude of HAND among people with HIV in Ethiopia. Therefore, this systematic review and meta-analysis aimed to estimate the prevalence of HAND in Ethiopia. Methods Following the PRISMA guidelines, we systematically reviewed and meta-analyzed studies that investigated the prevalence of HAND in Ethiopia from PubMed, Google Scholar, Science Direct, HINARI, EMBASE, and Cochrane library databases. We also looked at the reference lists of the included studies to include other relevant studies. Subgroup analysis was performed based on publication year, study location, and sample size. Heterogeneity across studies was evaluated using the I2 test. Potential publication bias was assessed using Egger’s test and visual inspection of symmetry in the funnel plots. Results In the present meta-analysis, 627 articles were initially identified and evaluated. Of these, 8 studies that met the inclusion criteria were included in the final analysis. The pooled prevalence of HAND in people with HIV in Ethiopia was 39.15% (95% CI 29.36, 48.94). The highest prevalence observed in the Southern Nations, Nationalities, and Peoples’ Region (SNNPR) with 53.20% (95% CI 25.96, 80.44) followed by others 34.87% (Tigray, Addis Ababa, and Oromia) (95% CI 33.49, 36.24) and Amhara 34.07% (95% CI 25.39, 42.74).The funnel plot was asymmetrical. However, Egger’s regression tests provided no evidence of publication bias in the prevalence of HAND. Conclusion In this meta-analysis, the pooled prevalence of HAND, in Ethiopia, was high. Older age, substance use, advanced stages of the disease, and lack of education were the main determinants of HAND in Ethiopia. Health education, early screening of people with HIV, and training of health professionals working in hospitals on HAND are highly recommended.

Aboveground Biomass of Living Trees Depends on Topographic Conditions and Tree Diversity in Temperate Montane Forests from the Slătioara-Rarău Area (Romania)

The study zone includes one of the largest montane old-growth forests in Europe (Slatioara UNESCO site), and understanding the structure and functioning of sill intact forests in Europe is essential for grounding management strategies for secondary forests. For this reason, we set out to analyze the dependencies between aboveground biomass (AgB), tree species and size diversity and terrain morphology, as well as the relationship between biomass and diversity, since neither of these issues have been sufficiently explored. We found that tree species diversity decreases with increased solar radiation and elevation. Tree size heterogeneity reaches its highest mean values at elevations between 1001 and 1100 m, on slopes between 50 and 60 degrees. AgB is differentiated with elevation; the highest mean AgB (293 tonnes per hectare) is recorded at elevations between 801 and 900 m, while it decreases to 79 tonnes per hectare at more than 1500 m a.s.l. It is also influenced by tree species diversity and tree size heterogeneity, with the highest AgB reached in the most complex forest ecosystems in terms of structural diversity. We showed that intact temperate montane forests develop maximum biomass for optimum species diversity and highest size heterogeneity; all three are modulated mainly by elevation.

Towards a Better Characterisation of Leukemic Cells in Chronic Lymphocytic Leukaemia: Cell-Size Heterogeneity Reflects Their Activation Status and Migratory Abilities

Chronic lymphocytic leukaemia (CLL) is a genetically, morphologically and phenotypically heterogeneous chronic disease with clinical variability between patients. Whether the significant heterogeneity of cell size within the CLL population contributes to the heterogeneous features of this disease has not been investigated. The present study aimed to characterise the phenotypic and functional properties of two subpopulations of typical CLL cells that differ in cell size: small (s-CLL) and large (l-CLL) CLL cells delineated by forward scatter cytometry. The s-CLL cells were characterised by the CD5lowCXCR4hi phenotype, while the l-CLL cells were characterised by the CD5hiCXCR4dim phenotype and indicated a higher expression of CXCR3, CD20, CD38 and HLA-DR. The l-CLL cells displayed higher migration activity towards CXCL12, a tendency towards a higher proliferation rate and an increased capacity to produce IgM in the presence of CpG compared with s-CLL cells. When stimulated with CpG and CXCL12, l-CLL cells were characterised by a higher polarisation phenotype and motility than s-CLL cells. Our study revealed that the differences in CLL cell size reflected their activation status, polarisation and migratory abilities. Our data provide evidence of the importance of cell-size heterogeneity within a CLL pool and the dynamics of cell-size changes for disease pathogenesis, thus deserving further investigation.

The impact of ownership and size heterogeneity on hotel efficiency in the Canary Islands (Spain)

This study was conducted to analyse the influence of technological differences on hotel efficiency in the Canary Islands (Spain), with particular regard to the heterogeneity observed in hotel ownership and size. A metafrontier approach, based on non-parametric deterministic efficiency methods (data envelopment analysis and free-disposal hull) and robust non-parametric estimators (order-α), is used. This empirical analysis considered a panel data sample selection model of Canary Islands hotels for the period 2002–2015. The results obtained show that the frontiers against which the hotels are compared (metafrontier or group) and the consideration or otherwise of outliers are factors of crucial importance. We find that efficiency depends on hotel size (large hotels are more efficient than small ones), but not on the type of ownership. The results also show that the impact of the global financial crisis on the average technical efficiency of these hotels was slight or non-existent. Finally, the technological gap narrowed over time, especially in large hotels and those with no majority shareholder.

Effect of density and mixed culture of largemouth bass (Micropterus salmoides) and pikeperch (Sander lucioperca) on growth, survival and feed conversion rate in intensive culture

In this study, two experiments were performed with the aim to optimize intensive aquaculture of largemouth bass (Micropterus salmoides). In the first 140-day experiment the effect of the initial fish density was assessed at three levels: low density (LD) 23 kg/m³, medium density (MD) 35 kg/m³ and high density (HD) 46 kg/m³. All three densities provided the same final Fulton’s condition coefficient (FC = 1.24–1.28), specific growth rate (SGR = 0.22–0.24%/day) and survival rate (97–100%). No cannibalism was observed at all tested densities. Feed conversion ratio (FCR = 1.39 ± 0.21 g/g) was the lowest for LD and the highest (1.61 ± 0.08 g/g) for MD. The highest fish biomass (25.7 ± 2.7 kg/m³) was obtained at HD and this density was considered as the most effective density of all tested ones during the intensive culture of largemouth bass. The second 60-day experiment tested the effect of largemouth bass and pikeperch (Sander lucioperca) monoculture and biculture of both species on production efficiency. Higher size heterogeneity was obtained in both (mono- and bicultural) groups of pikeperch (308.91–314.56‰/day) compared to the groups of largemouth bass (279.26–284.05 ‰/day). The higher FC (1.09) was found in both types of culture in largemouth bass compared to both methods of culture in pikeperch (0.74–0.78). The lowest SGR was evident in both types of largemouth bass cultures (1.20–1.28%/day). In contrast, the highest SGR was achieved in the bicultural pikeperch (1.88%/day). Similar results like for SGR were also assessed for FCR, where the highest value of FCR was in both cultures of largemouth bass (1.44–1.48 g/g) compared to the lowest FCR in the bicultural of pikeperch (0.73 g/g). Largemouth bass in both tested types of culture had higher survival rates (99.95–99.99%) compared to pikeperch (98.61–98.63%).

Tracking extracellular vesicle (EV) cargo as a platform for studying EVomics, signaling, and targeting in vivo

Extracellular vesicle (EV)-based signaling is a challenge to study, due to EV small size, heterogeneity, and limited information on cargo content in vivo. We present Caenorhabditis elegans as a discovery platform that allows single EV tracking from source to target tissue in living animals. We enriched ciliary EVs using GFP-tagged PKD-2 cargo followed by mass spectrometry analysis to identify 2,888 cargo candidates. By integrating our dataset with single-cell transcriptomic data, we identified EV cargo produced by individual neurons and other cell and tissue types. A single cilium produces multiple EVs with distinct protein content. Ciliary EVs carry nucleic acid binding proteins. We observed transfer of EV cargo from the male reproductive tract to the hermaphrodite uterus during mating, a direct demonstration of animal-to-animal EV targeting.