Variation of photosynthetic performance, nutrient uptake, and elemental composition of different generations and different thallus parts of Saccharina japonica

In order to illustrate the physiological variation of different generations and different thallus parts of Saccharina japonica, physiological parameters such as maximum and effective PSII photochemical efficiency, nutrient uptake, and elemental composition were determined in the laboratory. Photosynthetic analysis in different generations indicated that, although gametophytes had higher pigment contents than the sporophyte, they had lower values of F _v/F _m and ΔF/F′_m. The highest Chl a/Chl c ratio was found in sporophyte generation (3.98?±?0.01) and in the basal part of fresh thallus (2.66?±?0.02). The sporophyte had significantly higher values of nitrate uptake but lower values of phosphorus uptake than the gametophytes. The contents of nitrogen and carbon as well as C/N in gametophytes were significantly higher than those in sporophytes. In addition, the basal part of the S. japonica thallus had the highest C content (22.31?±?1.50 %) but the lowest N content (2.02?±?0.16 %), as well as the highest value of C/N (11.02?±?0.34).     

MitoQ,a mitochondria-targeted antioxidant,delays disease progression and alleviates pathogenesis in an experimental autoimmune encephalomyelitis mouse model of multiple sclerosis

Oxidative stress and mitochondrial dysfunction are involved in the progression and pathogenesis of multiple sclerosis (MS). MitoQ is a mitochondria-targeted antioxidant that has a neuroprotective role in several mitochondrial and neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. Here we sought to determine the possible effects of a systematic administration of MitoQ as a therapy, using an experimental autoimmune encephalomyelitis (EAE) mouse model. We studied the beneficial effects of MitoQ in EAE mice that mimic MS like symptoms by treating EAE mice with MitoQ and pretreated C57BL6 mice with MitoQ plus EAE induction. We found that pretreatment and treatment of EAE mice with MitoQ reduced neurological disabilities associated with EAE. We also found that both pretreatment and treatment of the EAE mice with MitoQ significantly suppressed inflammatory markers of EAE, including the inhibition of inflammatory cytokines and chemokines. MitoQ treatments reduced neuronal cell loss in the spinal cord, a factor underlying motor disability in EAE mice. The neuroprotective role of MitoQ was confirmed by a neuron-glia co-culture system designed to mimic the mechanism of MS and EAE in vitro. We found that axonal inflammation and oxidative stress are associated with impaired behavioral functions in the EAE mouse model and that treatment with MitoQ can exert protective effects on neurons and reduce axonal inflammation and oxidative stress. These protective effects are likely via multiple mechanisms, including the attenuation of the robust immune response. These results suggest that MitoQ may be a new candidate for the treatment of MS.     

Histochemical Studies of the Non‐Host Resistance and the Role of Actin Cytoskeleton in Pepper Against Colletotrichum orbiculare

The penetration process and defence reactions (hypersensitive response, oxidative burst and cell wall fortification) of Colletotrichum orbiculare were studied histochemically on pepper cultivar ‘A11’ (non‐host) and susceptible cucumber cultivar ‘Changchun Thorn’ (host). The results indicate that C. orbiculare could hardly penetrate the non‐host pepper leaves. It was papillae rather than hypersensitive response and H₂O₂ that played an important role in resisting the colonization and development of C. orbiculare on the non‐host pepper. The depolymerization of the actin microfilament weakened the papilla deposition of pepper and allowed successful penetration of the non‐adapted C. orbiculare, suggesting that the actin cytoskeleton of pepper is significant in preventing the invasion of the non‐host pathogen C. orbiculare.     

Instrumented Indentation Investigation on the Viscoelastic Properties of Porcine Cartilage

Articular cartilage lubricates the contact surfaces in human joints and provides a shock-absorbing effect which protects the joint under dynamic loading. However, this shock-absorbing effect is gradually reduced as the result of normal wear, tear and aging-related cartilage loss. Thus, with the increasing average human life expectancy, the issue of joint health has attracted significant interest in recent decades. In developing new materials for the repair or regeneration of damaged articular cartilage, it is essential that the difference in the mechanical properties of healthy and damaged cartilages is well-understood. In the present study, the hardness and Young＇s modulus of damaged and healthy porcine articular cartilage samples are evaluated via a quasi-static nanoindentation technique. A dynamic mechanical analysis method is then applied to determine the viscoelastic properties of the two samples. The results presented in this study provide a useful insight into the mechanical properties of articular cartilage at the mesoscale, and therefore fill an important gap in the literature.     

Effects of sand burial depth on the root system of Salix cheilophila seedlings in Mu Us Sandy Land, Inner Mongolia, China

Salix cheilophila Schneid. is a naturally occurring Salix species in Mu Us Sandy Land, Inner Mongolia, China. We focused on the morphological adaptability of S. cheilophila to sand dune burial. For morphological measurements, 32 S. cheilophila seedlings were removed from a community which was in the process of being buried by a shifting sand dune. Each seedling collected included the entire root system. We measured the number, length, and biomass of the adventitious roots, primary lateral roots, and taproot, and compared the morphological characteristics of the root system, including adventitious roots, for seedlings buried to various levels in the sand. The growth range of adventitious roots increased as the length of the buried portion of the main shoot increased. In addition, the total dry weight of all current-year shoots tended to increase gradually with increasing total dry weight of the adventitious roots. These results suggest that S. cheilophila tends to make use of the sedimentary sand layer that accompanies shifting sand dunes. However, there was no correlation between biomass or number of adventitious roots and the length of the buried part of the main shoot. Thus, S. cheilophila does not grow adventitious roots proportional to the buried part. These morphological characteristics of the root system, including the adventitious roots, may indicate that S. cheilophila has poor morphological adaptability to sand dune burial.     

Oxidized Low Density Lipoprotein Induced Caspase-1 Mediated Pyroptotic Cell Death in Macrophages: Implication in Lesion Instability?

Background

Macrophage death in advanced lesion has been confirmed to play an important role in plaque instability. However, the mechanism underlying lesion macrophage death still remains largely unknown.

Methods and Results

Immunohistochemistry showed that caspase-1 activated in advanced lesion and co-located with macrophages and TUNEL positive reaction. In in-vitro experiments showed that ox-LDL induced caspase-1 activation and this activation was required for ox-LDL induced macrophages lysis, IL-1β and IL-18 production as well as DNA fragmentation. Mechanism experiments showed that CD36 and NLRP3/caspase-1/pathway involved in ox-LDL induced macrophage pyroptosis.

Conclusion

Our study here identified a novel cell death, pyroptosis in ox-LDL induced human macrophage, which may be implicated in lesion macrophages death and play an important role in lesion instability.     

Diabetes Mellitus and Risk of Bladder Cancer: A Meta-Analysis of Cohort Studies

Objective

Diabetes is associated with increased risk of cancer at several sites, but its association with risk of bladder cancer is still controversial. We examined this association by conducting a systematic review and meta-analysis of cohort studies.

Methods

Studies were identified by searching PubMed, EMBASE, Scopus, Web of Science, Cochrane register, and Chinese National Knowledge Infrastructure (CNKI) databases through April 29, 2012. Summary relative risks (SRRs) with their corresponding 95% confidence intervals (CIs) were calculated using a random-effects model.

Results

A total of fifteen cohort studies were included in this meta-analysis. Analysis of all studies showed that diabetes was associated with a borderline statistically significant increased risk of bladder cancer (RR 1.11, 95% CI 1.00–1.23; p<0.001 for heterogeneity; I² = 84%). When restricting the analysis to studies that had adjusted for cigarette smoking (n = 6) or more than three confounders (n = 7), the RRs were 1.32 (95% CI 1.18–1.49) and 1.20 (95% CI 1.02–1.42), respectively. There was no significant publication bias (p = 0.62 for Egger’s regression asymmetry test).

Conclusions

Our findings support that diabetes was associated with an increased risk of bladder cancer. More future studies are warranted to get a better understanding of the association and to provide convincing evidence for clinical practice in bladder cancer prevention.     

Comparative Analysis of CpG Islands among HBV Genotypes

DNA methylation is being increasingly recognized to play a role in regulation of hepatitis B virus (HBV) gene expression. The aim of this study was to compare the CpG island distribution among different HBV genotypes. We analyzed 176 full-length HBV genomic sequences obtained from the GenBank database, belonging to genotypes A through J, to identify the CpG islands in the HBV genomes. Our results showed that while 79 out of 176 sequences contained three conventional CpG islands (I–III) as previously described, 83 HBV sequences harbored only two of the three known islands. Novel CpG islands were identified in the remaining 14 HBV isolates and named as CpG island IV, V, and VI. Among the eight known HBV genotypes and two putative genotypes, while HBV genomes containing three CpG islands were predominant in genotypes A, B, D, E, and I; genotypes C, F, G, and H tended to contain only two CpG islands (II and III). In conclusion, the CpG islands, which are potential targets for DNA methylation mediated by the host functions, differ among HBV genotypes, and these genotype-specific differences in CpG island distribution could provide new insights into the understanding of epigenetic regulation of HBV gene expression and hepatitis B disease outcome.