Calcium-dependent aggregation of human serum amyloid P component: Inhibition by the cyclic 4,6-pyruvate acetal of galactose

Serum amyloid P component is a normal plasma glycoprotein which is the precursor of amyloid P component, a minor but universal constituent of amyloid deposits. When isolated human P component is exposed to free ionised Ca²⁺ it aggregates and precipitates. This phenomenon is completely inhibited by the presence of 10^?4?10^?2 M methyl 4,6-O-(1-car?yethylidene)-β-D-galactopyranoside, a recently synthesised specific ligand for amyloid P component. This observation suggests that the autoaggregation of human amyloid P component involves the Ca²⁺ dependent specific ligand binding property of P component, but does not distinguish between receptor-site-mediated and allosteric mechanisms.     

Me2SO- and serum-free cryopreservation of human umbilical cord mesenchymal stem cells using electroporation-assisted delivery of sugars

Cryopreservation is the universal technology used to enable long-term storage and continuous availability of cell stocks and tissues for regenerative medicine demands. The main components of standard freezing media are dimethyl sulfoxide (hereinafter Me₂SO) and fetal bovine serum (FBS). However, for manufacturing of cells and tissue-engineered products in accordance with the principles of Good Manufacturing Practice (GMP), current considerations in regenerative medicine suggest development of Me₂SO- and serum-free biopreservation strategies due to safety concerns over Me₂SO-induced side effects and immunogenicity of animal serum.In this work, the effect of electroporation-assisted pre-freeze delivery of sucrose, trehalose and raffinose into human umbilical cord mesenchymal stem cells (hUCMSCs) on their post-thaw survival was investigated. The optimal strength of electric field at 8 pulses with 100 μs duration and 1 Hz pulse repetition frequency was determined to be 1.5 kV/cm from permeabilization (propidium iodide uptake) vs. cell recovery data (resazurin reduction assay).Using sugars as sole cryoprotectants with electroporation, concentration-dependent increase in cell survival was observed. Irrespective of sugar type, the highest cell survival (up to 80%) was achieved at 400 mM extracellular concentration and electroporation. Cell freezing without electroporation yielded significantly lower survival rates. In the optimal scenario, cells were able to attach 24 h after thawing demonstrating characteristic shape and sugar-loaded vacuoles. Application of 10% Me₂SO/90% FBS as a positive control provided cell survival exceeding 90%. Next, high glass transition temperatures determined for optimal concentrations of sugars by differential scanning calorimetry (DSC) suggest the possibility to store samples at −80 °C. In summary, using electroporation to incorporate cryoprotective sugars into cells is an effective strategy towards Me₂SO- and serum-free cryopreservation and may pave the way for further progress in establishing clinically safe biopreservation strategies for efficient long-term biobanking of cells.     

Induction of bystander effects by UVA,UVB, and UVC radiation in human fibroblasts and the implication of reactive oxygen species

Radiation-induced bystander effects are various types of responses displayed by nonirradiated cells induced by signals transmitted from neighboring irradiated cells. This phenomenon has been well studied after ionizing radiation, but data on bystander effects after UV radiation are limited and so far have been reported mainly after UVA and UVB radiation. The studies described here were aimed at comparing the responses of human dermal fibroblasts exposed directly to UV (A, B, or C wavelength range) and searching for bystander effects induced in unexposed cells using a transwell co-incubation system. Cell survival and apoptosis were used as a measure of radiation effects. Additionally, induction of senescence in UV-exposed and bystander cells was evaluated. Reactive oxygen species (ROS), superoxide radical anions, and nitric oxide inside the cells and secretion of interleukins 6 and 8 (IL-6 and IL-8) into the medium were assayed and evaluated as potential mediators of bystander effects. All three regions of ultraviolet radiation induced bystander effects in unexposed cells, as shown by a diminution of survival and an increase in apoptosis, but the pattern of response to direct exposure and the bystander effects differed depending on the UV spectrum. Although UVA and UVB were more effective than UVC in generation of apoptosis in bystander cells, UVC induced senescence both in irradiated cells and in neighbors. The level of cellular ROS increased significantly shortly after UVA and UVB exposure, suggesting that the bystander effects may be mediated by ROS generated in cells by UV radiation. Interestingly, UVC was more effective at generation of ROS in bystanders than in directly exposed cells and induced a high yield of superoxide in exposed and bystander cells, which, however, was only weakly associated with impairment of mitochondrial membrane potential. Increasing concentration of IL-6 but not IL-8 after exposure to each of the three bands of UV points to its role as a mediator in the bystander effect. Nitric oxide appeared to play a minor role as a mediator of bystander effects in our experiments. The results demonstrating an increase in intracellular oxidation, not only in directly UV-exposed but also in neighboring cells, and generation of proinflammatory cytokines, processes entailing cell damage (decreased viability, apoptosis, senescence), suggest that all bands of UV radiation carry a potential hazard for human health, not only due to direct mechanisms, but also due to bystander effects.     

An actuated dissipative spring-mass walking model: Predicting human-like ground reaction forces and the effects of model parameters

Simple models are widely used to understand the mechanics of human walking. The optimization-based minimal biped model and spring-loaded-inverted-pendulum (SLIP) model are two popular models that can achieve human-like walking patterns. However, ground reaction forces (GRF) from these two models still deviate from experimental data. In this paper, we proposed an actuated dissipative spring-mass model by integrating these two models to realize more human-like GRF patterns. We first explored the function of stiffness, damping, and weights of both energy cost and force cost in the objective function and found that these parameters have distinctly different influences on the optimized gait and GRF profiles. The stiffness and objective weight affect the number and size of peaks in the vertical GRF and stance time. The damping changes the relative size of the peaks but has little influence on stance time. Based on these observations, these parameters were manually tuned at three different speeds to approach experimentally measured vertical GRF and the highest correlation coefficient can reach 0.983. These results indicate that the stiffness, damping, and proper objective functions are all important factors in achieving human-like motion for this simple walking model. These findings can facilitate the understanding of human walking dynamics and may be applied in future biped models.     

Prominent role of volcanism in Common Era climate variability and human history

Climate reconstructions for the Common Era are compromised by the paucity of annually-resolved and absolutely-dated proxy records prior to medieval times. Where reconstructions are based on combinations of different climate archive types (of varying spatiotemporal resolution, dating uncertainty, record length and predictive skill), it is challenging to estimate past amplitude ranges, disentangle the relative roles of natural and anthropogenic forcing, or probe deeper interrelationships between climate variability and human history. Here, we compile and analyse updated versions of all the existing summer temperature sensitive tree-ring width chronologies from the Northern Hemisphere that span the entire Common Era. We apply a novel ensemble approach to reconstruct extra-tropical summer temperatures from 1 to 2010 CE, and calculate uncertainties at continental to hemispheric scales. Peak warming in the 280s, 990s and 1020s, when volcanic forcing was low, was comparable to modern conditions until 2010 CE. The lowest June–August temperature anomaly in 536 not only marks the beginning of the coldest decade, but also defines the onset of the Late Antique Little Ice Age (LALIA). While prolonged warmth during Roman and medieval times roughly coincides with the tendency towards societal prosperity across much of the North Atlantic/European sector and East Asia, major episodes of volcanically-forced summer cooling often presaged widespread famines, plague outbreaks and political upheavals. Our study reveals a larger amplitude of spatially synchronized summer temperature variation during the first millennium of the Common Era than previously recognised.     

T-bet+ Memory B Cells Link to Local Cross-Reactive IgG upon Human Rhinovirus Infection

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Effects of the Addition of Humic Substances on Soil Protease Activities in Andosols in the Presence of Cadmium

Cadmium extraction, sorption, and immobilization seem to be the effective mechanisms in detoxification of Cd-contaminated soil. Humic substances present in soils may play an important role both in controlling the negative effects of pollution with Cd and in stabilizing soil enzymes. In this context, we have compared the effects of humic substances on soil protease activities in the presence and absence of Cd in forest and cultivated field soil samples. The samples were taken from surface soils of Andosols in a single upland area of the Kanto district in Japan. Humic substances extracted from the two soils showed differences in elemental composition, the degree of condensation of aromatic groups, and the proportions of major functional groups. Compared with the control soil samples, those with added humic substances showed a significant increase in protease activities, even in the presence of Cd (10 and 50 mg Cd kg^?1 soil). However, the addition of Cd decreased the protease activities, protein contents, and soil pH in both soil samples at each of the two levels of humic substance fortification (+5% and +10%). Moreover, protease activities showed significant negative correlation with exchangeable Cd, but adding humic substances did not lead to a reduction in either sample. Thus, although the addition of humic substances increased and stabilized protease activities, it did not lead to a clear reversal of enzyme inhibition by Cd. The obtained results indicate that in both soil samples the humic substances used in this study did not have sufficient affinity to adsorb Cd, and the impact on enzyme activities depends on the difference in chemical characteristics of the added organic matter, as suggested by the difference in enhancement of protease activities between forest and cultivated field soil samples.     

Identification of gonadotropic and antigonadotropic factors from the nervous part of the corpora cardiaca in the African locust

Summary

The nervous part of the locust corpora cardiaca (NCC) was extracted using 70% methanol and subjected to fast protein liquid chromatography (FPLC). Twenty fractions were collected and injected into females from the end of the IIIrd larval instar to day-12 of the adult life to screen the effects on metamorphosis, body pigmentation, and oocyte growth. The rate of juvenile hormone (JH) biosynthesis by the corpora allata of injected animals was evaluated in vitro. One fraction was found to stimulate ovarian maturation, and 3 to delay oocyte growth. None of them disturbed (i) either metamorphosis and body color (which are JH dependent), or (ii) rate of JH biosynthesis. Of the 3 fractions which inhibited ovarian maturation, 2 of them were identified as the neuroparsins A and B. The results clearly illustrate that antagonist factors from the brain are involved in the regulation of ovarian maturation in the locust.     

Immunoregulatory effect of mesenchymal stem cell via mitochondria signaling pathways in allergic asthma

Asthma is a complicated lung disease, which has increased morbidity and mortality rates in worldwide. There is an overlap between asthma pathophysiology and mitochondrial dysfunction and MSCs may have regulatory effect on mitochondrial dysfunction and treats asthma. Therefore, immune-modulatory effect of MSCs and mitochondrial signaling pathways in asthma was studied.After culturing of MSCs and producing asthma animal model, the mice were treated with MSCs via IV via IT. BALf's eosinophil Counting, The levels of IL-4, −5, −13, −25, –33, INF-γ, Cys-LT, LTB4, LTC4, mitochondria genes expression of COX-1, COX-2, ND1, Nrf2, Cytb were measured and lung histopathological study were done.BALf's eosinophils, the levels of IL-4, −5, −13, −25, –33, LTB4, LTC4, Cys-LT, the mitochondria genes expression (COX-1, COX-2, Cytb and ND-1), perivascular and peribronchial inflammation, mucus hyper-production and hyperplasia of the goblet cell in pathological study were significantly decreased in MSCs-treated asthma mice and reverse trend was found about Nrf-2 gene expression, IFN-γ level and ratio of the INF-γ/IL-4.MSC therapy can control inflammation, immune-inflammatory factors in asthma and mitochondrial related genes, and prevent asthma immune-pathology.