No abstract

The goal of this study is to determine the effects of Insulin-Transferrin-Selenium (ITS) on proliferation of auricular chondrocytes and formation of engineered cartilage in vitro. Pig auricular monolayer chondrocytes and chondrocyte pellets were cultured in media containing 1% ITS at different concentrations of fetal bovine serum (FBS, 10%, 6%, 2%, 0%), or 10% FBS alone as a control for four weeks. Parameters including cell proliferation in monolayer, wet weight, collagen type I/II/X (Col I, II, X) and glycosaminoglycan (GAG) expression, GAG content of pellets and gene expression associated with cartilage formation/dedifferentiation (lost cartilage phenotype)/hypertrophy within the chondrocyte pellets were assessed. The results showed that chondrocytes proliferation rates increased when FBS concentrations increased (2%, 6%, 10% FBS) in ITS supplemented groups. In addition, 1% ITS plus 10% FBS significantly promoted cell proliferation than 10% FBS alone. No chondrocytes grew in ITS alone medium. 1% ITS plus 10% FBS enhanced cartilage formation in terms of size, wet weight, cartilage specific matrices, and homogeneity, compared to 10% FBS alone group. Furthermore, ITS prevented engineered cartilage from dedifferentiation (i.e., higher index of Col II/Col I mRNA expression and expression of aggrecan) and hypertrophy (i.e., lower mRNA expression of Col X and MMP13). In conclusion, our results indicated that ITS efficiently enhanced auricular chondrocytes proliferation, retained chondrogenic phenotypes, and promoted engineered cartilage formation when combined with FBS, which is potentially used as key supplementation in auricular chondrocytes and engineered cartilage culture.

No abstract

Uneven soil depth and low water availability are the key limiting factors to vegetation restoration and reconstruction in limestone soils such as in vulnerable karst regions. Belowground competition will possibly increase under limited soil resources. Here, we investigate whether low resource availability (including shallow soil, low water availability, and shallow soil and low water availability combined) stimulates the competition between grasses with different root systems in karst soil, by assessing their growth response, biomass allocation, and morphological plasticity. In a full three-way factorial blocked design of soil depth by water availability by neighbor identity, we grew Festuca arundinacea (deep-rooted) and Lolium perenne (shallow-rooted) under normal versus shallow soil depth, high versus low water availability, and in monoculture (conspecific neighbor) versus mixture (neighbor of the other species). The key results were as follows: (1) total biomass and aboveground biomass in either of the species decreased with reduction of resources but were not affected by planting patterns (monoculture or mixture) even at low resource levels. (2) For F. arundinacea, root biomass, root mass fraction, total root length, and root volume were higher in mixture than in monoculture at high resource level (consistent with resource use complementarity), but lower in mixture than in monoculture at low resource levels (consistent with interspecific competition). In contrast for L. perenne, either at high or low resource level, these root traits had mostly similar values at both planting patterns. These results suggest that deep-rooted and shallow-rooted plant species can coexist in karst regions under current climatic regimes. Declining resources, due to shallow soil, a decrease in precipitation, or combined shallow soil and karst drought, increased the root competition between plants of deep-rooted and shallow-rooted species. The root systems of deep-rooted plants may be too small to get sufficient water and nutrients from dry, shallow soil, while shallow-rooted plants will maintain a dominant position with their already adaptive strategy in respect of root biomass allocation and root growth.

This study aimed to explore the related factors and strengths of hepatic cirrhosis complicated with hepatic encephalopathy (HE) by multivariate logistic regression analysis and tabu search-based Bayesian networks (BNs), and to deduce the probability of HE in patients with cirrhosis under different conditions through BN reasoning. Multivariate logistic regression analysis indicated that electrolyte disorders, infections, poor spirits, hepatorenal syndrome, hepatic diabetes, prothrombin time, and total bilirubin are associated with HE. Inferences by BNs found that infection, electrolyte disorder and hepatorenal syndrome are closely related to HE. Those three variables are also related to each other, indicating that the occurrence of any of those three complications may induce the other two complications. When those three complications occur simultaneously, the probability of HE may reach 0.90 or more. The BN constructed by the tabu search algorithm can analyze not only how the correlative factors affect HE but also their interrelationships. Reasoning using BNs can describe how HE is induced on the basis of the order in which doctors acquire patient information, which is consistent with the sequential process of clinical diagnosis and treatment.

Soil pH varies by several units among ecosystems. While soil pH is known to be a key driver of plant species composition, we still have a poor understanding of how it affects carbon cycling processes. For instance, soil pH, or its associated chemistry in terms of base cations and organic acids, may affect decomposition rates of dead matter directly, by controlling decomposer composition and activity and, indirectly, by controlling the traits of the plant species and thereby the afterlife effects of those traits on litter decomposition. Leaf and litter pH may play a role in this control. Based on the very limited empirical data available, we hypothesized that variation in species traits including leaf (litter) pH, within and between ecosystems contrasting in soil pH, would have stronger effects on leaf litter decomposition rates than variation in soil chemistry would. We tested this hypothesis by carrying out a ‘common garden’ litterbed experiment in subtropical SW China, in which leaf litters of the 30 predominant plant species from mid‐successional forest on acidic sandstone (soil pH around 4.0) and calcareous soil (pH around 7.5), respectively, were incubated and their decomposition rates measured over two harvests in 14 months, both in soil plus litter matrix from their ‘home’ forest and in those from the ‘away’ forest. We found that leaf (litter) trait variation among species and plant functional types, headed by species' dry matter content but also including tissue pH, was the strongest driver of variation in leaf litter decomposition rates. Surprisingly, however, while these effects of interspecific trait variation were very strong among species from the same site, there was no overall difference in litter decomposability between the species from the acidic versus calcareous site. Equally surprising was that this strong difference in pH of soil substrate plus litter matrix from an acidic sandstone site versus a calcareous karst site did not directly affect leaf litter decomposition rates across a given species set. This first attempt to disentangle the multiple potential direct and indirect ways in which soil and leaf (litter) acidity might be related to litter decomposition rates has important implications for our understanding of soil–plant feedbacks. Based on our forest‐based study, we predict that soil–plant feedbacks via acidity are unlikely to be strong in ecosystems with wide‐ranging species in terms of their leaf functional traits, including leaf pH. A free Plain Language Summary can be found within the Supporting Information of this article.

For the application of bone marrow stromal cells (BMSCs) in cartilage tissue engineering, it is imperative to develop efficient strategies for their chondrogenic differentiation. In this study, the conditioned media derived from chondrocyte/scaffold constructs were used to direct chondrogenic differentiation of BMSCs. The porcine articular chondrocytes were seeded on the PGA/PLA scaffolds to form chondrocyte/scaffold constructs and were cultured to form engineered cartilage in vitro. The culture media were collected as conditioned media and used for chondrogenic induction of BMSC pellets (experimental group, Exp.). The chondrocyte pellets and BMSC pellets were cultured routinely as positive control (PC) and negative control (NC), respectively. After 4 weeks, the wet weight and GAG content in Exp. group and PC group were significantly higher than that in NC group. Histological and immunohistochemical analysis showed that cartilaginous tissue was formed with typical cartilage lacuna structure and positive staining of collagen Type II (Col II) in the peripheral area of the BMSC pellets in Exp. group. Gene expression of Sox9, Col II, and COMP in Exp. group and PC group were significantly higher than that in NC group. The growth factors in the conditioned media derived from human costal chondrocytes-scaffold constructs were tested by protein microassay. The conditioned media contained low levels of TGF-b1,2,3, IGF-1 and high levels of IGF-2, FGF-4, and IGFBP4,6, and so forth. The soluble factors derived from the engineered cartilage can induce chondrogenic differentiation of BMSCs independently. Many cytokines may function in chondrogenesis in a coordinated way.

AIM:To explore the mechanism of intestinal endotoxemia (IETM) formation and its changes in partially hepatectomized (PH) rats. METHODS:One-hundred and two adult male Wistar rats were randomly divided into three groups: normal control (NC) group, partially hepatectomized (PH) group and a sham-operated (SO) group. To study the dynamic changes, rats were sacrificed before and at different time points after partial hepatectomy or the sham-operation ( 6 h, 12 h, 24 h, 36 h, 48 h, 72 h, 120 h and 168 h). NC group was used as 0h time point in observation, namely 0 h group. For each time point indicated, six rats were used in parallel. Endotoxin (ET) and diamine oxidase (DAO) levels were determined in serum using Limulus Lysate test with chromogenic substrate and spectrophotometry. Intestinal mucosa barrier was observed under optical or electron microscope. The number and functional state of Kupffer cells (KCs) in the remnant regenerating liver were measured by immunohistochemical staining. RESULTS:Serum ET levels significantly increased during 6-72 h period after PH compared with NC and SO groups, and there were two peak values at 12 and 48 h while serum DAO level significantly increased at 12 and 24 h. There was positive correlation (r = 0.757, P < 0.05) between the levels of DAO and ET dynamic changes. The optical examination showed neutrophil margination and superficial necrosis of the villi in the intestinal mucosa during 6-24 h period after PH. The penetrated electron microscope examination showed that the gaps between intestinal mucosa cells were increased and the Lanthanum (La) particles were observed among the intestinal mucosa cells during 6-48 h period. The numbers of KCs in the remnant regenerating liver were significantly increased during 24-168 h period after PH. However, the activation of KCs was predominantly observed at 48 h after PH. CONCLUSION:The mechanism of IETM in PH rats might be the injury of intestinal mucosa barrier and the decrease of the absolute number of KCs as well as the depression of functional state of KCs. This observation is of potential value in patients undergoing liver resection.