A simplified, data-constrained approach to estimate the permafrost carbon-climate feedback

We present an approach to estimate the feedback from large-scale thawing of permafrost soils using a simplified, data-constrained model that combines three elements: soil carbon (C) maps and profiles to identify the distribution and type of C in permafrost soils; incubation experiments to quantify the rates of C lost after thaw; and models of soil thermal dynamics in response to climate warming. We call the approach the Permafrost Carbon Network Incubation-Panarctic Thermal scaling approach (PInc-PanTher). The approach assumes that C stocks do not decompose at all when frozen, but once thawed follow set decomposition trajectories as a function of soil temperature. The trajectories are determined according to a three-pool decomposition model fitted to incubation data using parameters specific to soil horizon types. We calculate litterfall C inputs required to maintain steady-state C balance for the current climate, and hold those inputs constant. Soil temperatures are taken from the soil thermal modules of ecosystem model simulations forced by a common set of future climate change anomalies under two warming scenarios over the period 2010 to 2100. Under a medium warming scenario (RCP4.5), the approach projects permafrost soil C losses of 12.2-33.4 Pg C; under a high warming scenario (RCP8.5), the approach projects C losses of 27.9-112.6 Pg C. Projected C losses are roughly linearly proportional to global temperature changes across the two scenarios. These results indicate a global sensitivity of frozen soil C to climate change (γ sensitivity) of -14 to -19 Pg C °C(-1) on a 100 year time scale. For CH4 emissions, our approach assumes a fixed saturated area and that increases in CH4 emissions are related to increased heterotrophic respiration in anoxic soil, yielding CH4 emission increases of 7% and 35% for the RCP4.5 and RCP8.5 scenarios, respectively, which add an additional greenhouse gas forcing of approximately 10-18%. The simplified approach presented here neglects many important processes that may amplify or mitigate C release from permafrost soils, but serves as a data-constrained estimate on the forced, large-scale permafrost C response to warming.

Heterogeneous vesicles in mucous epithelial cells of posterior esophagus of Chinese giant salamander (Andrias davidianus)

The Chinese giant salamander belongs to an old lineage of salamanders and endangered species. Many studies of breeding and disease regarding this amphibian had been implemented. However, the studies on the ultrastructure of this amphibian are rare. In this work, we provide a histological and ultra-structural investigation on posterior esophagus of Chinese giant salamander. The sections of amphibian esophagus were stained by hematoxylin & eosin (H&E). Moreover, the esophageal epithelium was observed by transmission electron microscopy (TEM). The results showed that esophageal epithelium was a single layer epithelium, which consisted of mucous cells and columnar cells. The esophageal glands were present in submucosa. The columnar cells were ciliated. According to the diverging ultrastructure of mucous vesicles, three types of mucous cells could be identified in the esophageal mucosa: i) electron-lucent vesicles mucous cell (ELV-MC); ii) electron-dense vesicles mucous cell (EDV-MC); and iii) mixed vesicles mucous cell (MV-MC).

Has racial difference in cause-specific death improved in older patients with late-stage breast cancer?

BACKGROUND

Research on temporal mortality trends for stage IV breast cancer is limited, especially among older patients by race. We evaluated factors associated with overall, breast cancer-specific and other-cause mortalities using contemporary population data.

PATIENTS AND METHODS

Using the Surveillance, Epidemiology, and End Results-Medicare linked data, we identified older women (≥ 66 years) with stage IV breast cancer diagnosed in 2002-2009. Overall mortality was estimated by the Kaplan-Meier method, compared by log-rank tests, and modeled by Cox models. Competing risk analysis was used to evaluate breast cancer-specific and other-cause mortalities.

RESULTS

The median overall survival time for non-Hispanic blacks improved from 8.6 months in 2002-2003 to 9.9 months in 2007-2009, whereas that for non-Hispanic whites improved from 12.1 to 14.8 months. In the multivariate model, the risk of breast cancer-specific death for patients diagnosed in 2007-2009 was significantly lower (P = 0.02), whereas the risk of other-cause mortality changed little (P = 0.88) compared with those risks for patients diagnosed in 2002-2003. Non-Hispanic blacks had the higher risk of both mortality types compared with non-Hispanic whites; a diagnosis time-race interaction term was not statistically significant for either cause of death.

CONCLUSION

Breast cancer-specific mortality among older women modestly improved from 2002 to 2009 across all races, but not other-cause mortality. Racial disparity in mortality persisted, but did not widen in this period. Efforts should be devoted to improving other-cause mortality for all women, with special attention toward decreasing breast cancer mortality for non-Hispanic black women.

TRAF3IP3, a novel autophagy up-regulated gene, is involved in marginal zone B lymphocyte development and survival

Tumour necrosis factor receptor-associated factor 3 (TRAF3) interacting protein 3 (TRAF3IP3; also known as T3JAM) is expressed specifically in immune organs and tissues. To investigate the impact of TRAF3IP3 on immunity, we generated Traf3ip3 knock-out (KO) mice. Interestingly, these mice exhibited a significant reduction in the number of common lymphoid progenitors (CLPs) and inhibition of B cell development in the bone marrow. Furthermore, Traf3ip3 KO mice lacked marginal zone (MZ) B cells in the spleen. Traf3ip3 KO mice also exhibited a reduced amount of serum natural antibodies and impaired T cell-independent type II (TI-II) responses to trinitrophenol (TNP)-Ficoll antigen. Additionally, our results showed that Traf3ip3 promotes autophagy via an ATG16L1-binding motif, and MZ B cells isolated from mutant mice showed a diminished level of autophagy and a high rate of apoptosis. These results suggest that TRAF3IP3 contributes to MZ B cell survival by up-regulating autophagy, thereby promoting the TI-II immune response.

Intravaginal HPV DNA vaccination with electroporation induces local CD8+ T-cell immune responses and antitumor effects against cervicovaginal tumors

Therapeutic human papillomavirus (HPV) vaccines have the potential to inhibit the progression of an established HPV infection to precancer and cancer lesions by targeting HPV oncoproteins. We have previously developed a therapeutic DNA vaccine encoding calreticulin (CRT) linked to E7, CRT/E7 DNA vaccine, for use in the treatment of HPV-associated lesions. Since the transfection efficiency of DNA vaccines administered in vivo is typically low, we examined the use of electroporation as well as different routes of administration to enhance antigen-specific tumor control. We tested the effects of the CRT/E7 DNA vaccine administered intramuscularly or intravaginally, with or without electroporation, on the generation of CD8+ T-cell immunity and therapeutic antitumor effects in HPV16 E7-expressing cervicovaginal tumor-bearing mice. We found that intravaginal vaccination of CRT/E7 DNA followed by electroporation-induced potent E7-specific CD8(+) T-cell responses in the cervicovaginal tract, compared with intramuscular injection followed by electroporation. Furthermore, tumor-bearing mice vaccinated intravaginally followed by electroporation had an enhanced survival, antitumor effects and local production of IFN-γ+CD8+ T cells compared with those vaccinated intramuscularly with electroporation. Thus, we show that intravaginal CRT/E7 DNA vaccination followed by electroporation generates the most potent therapeutic antitumor effects against an orthotopic E7-expressing tumor model. The current study will have significant clinical implications once a clinically applicable electroporation device for intravaginal use becomes available.

Transcriptional characteristics associated with lichenysin biosynthesis in Bacillus licheniformis from Chinese Maotai-flavor liquor making

This work investigated the biosynthetic mechanism of lichenysin, the newly identified nonvolatile matrix component in Chinese liquors. Transcriptomes were analyzed in three producers, Bacillus licheniformis CGMCC 3961, 3962, and 3963, which were isolated from Maotai-flavor liquor-making process and produced 386.3, 553.5, and 795.2 μg/L lichenysin in a simulative liquor fermentation process. Lichenysin synthetase genes lchAA-AD in these three producers were expressed much more highly than those of the nonproducer B. licheniformis ATCC 14580 (>18.4-fold). In addition, ABC transporters were the most significant responsive metabolic pathway, and the expression levels of peptide transporter genes dppABCDE all increased more than 19.2-fold. When B. licheniformis CGMCC 3963 was cultured in synthetic medium, the expression of dppABCDE and lichenysin both increased with the addition of casein hydrolysate (containing various peptides). This indicated that peptide would act as a substrate for lichenysin synthesis. This work sheds new light on the mechanism for lichenysin biosynthesis.

From the camp pathway to search the ketamine-related learning and memory

Protein kinase A (PKA) phosphorylates and activates cAMP response element-binding protein (CREB), which then binds to CRE domain on DNA and in turn activates genes involved in the process of learning and memorization. It has been demonstrated that CREB is involve in the learning and memory deficits that are caused by ketamine. In this review, we attempt to discuss the role of ketamine and cAMP pathway and relevant regulatory protein ERK in learning and memory through the molecular mechanism and signaling pathways. In this review, we also try to find a new way to treat the impairment in learning and memory induced by ketamine.

Explanation of colon cancer pathophysiology through analyzing the disrupted homeostasis of bile acids

BACKGROUND

The colon plays a key role in regulating the homeostasis of bile acids.

AIM

The present study aims to evaluate the influence of colon cancer towards the homeostasis of bile acids.

METHODS

The free and conjugated bile acids were determined using ultraperformance LC (UPLC) coupled with ABI 4000 QTRAP triple quadrupole instruments.

RESULTS

The results showed that the free bile acids in serum of patients with colon cancers tend to increase, and the conjugated bile acids tended to decrease, especially for taurolithocholate (TLCA) (p<0.001).

CONCLUSION

The alteration of bile acids balance in colon cancers indicated the possibility of complicated diseases due to the disrupted balance of bile acids.

The phosphodiesterase-4 inhibitor Ro 20-1724 reverses learning and memory impairments, and downregulation of CREB in the hippocampus and cortex induced by ketamine anesthesia in immature rats

AIM

The objective of the study was to examine the effects and possible mechanisms of phosphodiesterase-4 inhibitor Ro 20-1724 on learning and memory impairments induced by ketamine anesthesia. Further, expression the cAMP response element binding proteins (CREB), transcription factors involved in long-term memory, were analyzed in conjunction with these effects of Ro 20-1724.

METHODS

Ninety-six immature (21-day-old) Sprague-Dawley rats were divided into eight groups. To assess the learning and memory impairments, Morris Water Maze task was used. Expression of total and phosphorylated CREB in the hippocampus and cerebral cortex was evaluated by Western blot.

RESULTS

THE escape latency and frequency of passing the platform in Morris Water Maze task were markedly longer after ketamine anesthesia. However, treatment with Ro 20-1724 significantly (P<0.05) improved both learning and memory performance. Further, administration of Ro 20-1724 reverted the down-regulation of total and phosphorylated CREB caused by ketamine (P<0.05), as demonstrated by Western blot analysis of CREB expression in the hippocampus and cortex.

CONCLUSION

Treatment with Ro 20-1724 improves learning and memory deficits caused by ketamine anesthesia in immature rats, possibly via increases in expression of total and phosphorylated CREB in the hippocampus and cerebral cortex.

Expression profile of Nanos2 gene in dairy goat and its inhibitory effect on Stra8 during meiosis

OBJECTIVES

Nanos2, an RNA-binding protein, belongs to the Nanos gene-coding family and contains two CCHC zinc-finger motifs. In mouse, it plays a pivotal role in male germ cell development, and self-renewal of spermatogonial stem cells. However, little is known of its expression pattern and functions in dairy goat testis.

MATERIALS AND METHODS

Immunohistochemistry and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were used to generate the expression profile of Nanos2 in dairy goat testis. Furthermore, its overexpression effects on male germline stem cells (mGSCs) were studied using qRT-PCR, immunofluorescence, dual-luciferase reporter assay and western blotting.

RESULTS

Nanos2 is a conservative gene expressed widely in various tissues, especially in pancreas, and it displays higher expression in adult testes than in other age groups. Overexpression of Nanos2 significantly downregulated meiosis-related genes, including Stra8 and Scp3, which induced inhibition of meiosis. Results from dual-luciferase reporter assay and western blotting indicated that Nanos2 directly downregulated Stra8 in goat GmGSCs.

CONCLUSIONS

Taken together, these results suggest that Nanos2 plays an important role in spermatogonia and that its overexpression restrained meiosis in the dairy goat.