Lipid droplets in pathogen infection and host immunity.

As the hub of cellular lipid metabolism, lipid droplets (LDs) have been linked to a variety of biological processes. During pathogen infection, the biogenesis, composition, and functions of LDs are tightly regulated. The accumulation of LDs has been described as a hallmark of pathogen infection and is thought to be driven by pathogens for their own benefit. Recent studies have revealed that LDs and their subsequent lipid mediators contribute to effective immunological responses to pathogen infection by promoting host stress tolerance and reducing toxicity. In this comprehensive review, we delve into the intricate roles of LDs in governing the replication and assembly of a wide spectrum of pathogens within host cells. We also discuss the regulatory function of LDs in host immunity and highlight the potential for targeting LDs for the diagnosis and treatment of infectious diseases.

Estimating the burden of foodborne gastroenteritis due to nontyphoidal Salmonella enterica, Shigella and Vibrio parahaemolyticus in China.

To estimate the incidence of foodborne gastroenteritis caused by nontyphoidal Salmonella enterica, Shigella, and Vibrio parahaemolyticus in China, population surveys and sentinel hospital surveillance were implemented in six provinces from July 2010 to July 2011, and a multiplier calculation model for the burden of disease was constructed. The multiplier for salmonellosis and V. parahaemolyticus gastroenteritis was estimated at 4,137 [95% confidence interval (CI) 2,320-5,663], and for shigellosis at 4,356 (95% CI 2,443-5,963). Annual incidence per 100,000 population was estimated as 245 (95% CI 138-336), 67 (95% CI 38-92), and 806 (95% CI 452-1,103) for foodborne salmonellosis, shigellosis, and V. parahaemolyticus gastroenteritis, respectively, indicating that foodborne infection caused by these three pathogens constitutes an important burden to the Chinese healthcare system. Continuous implementation of active surveillance of foodborne diseases, combined with multiplier models to estimate disease burden, makes it possible for us to better understand food safety status in China.

The order of multiple excited state proton transfer in ternary complex of norharmane and acetic acids.

Dolores Reyman et al. found the norharmane (9H-pyrido [3,4-b] indole) (NHM) and two acetic acid molecules can form the ternary complex (NHM-2A) in component solvent of dichloromethane and acetic acid via the hydrogen bond chain (J. Lumin. 2014, 148, 64). But the specific reaction details during this process were rarely reported. In this study, we will give an insight into the reasons which promote the occurrence of this reaction as well as its reaction order. The hydrogen bond enhancing behavior in first excited state (S1) is verified through the analysis of geometric configurations, infrared spectra, frontier molecular orbitals and potential energy curves. The absorption and fluorescence spectra we calculated are well coincident with the experimental results. Meanwhile, it is obvious that the hydrogen bond intensity is gradually enhanced from N1H2⋯O3, O4H5⋯O6 to O7H8⋯N9 by analyzing the reduced density gradient (RDG) isosurface. The hydrogen bond strengthening mechanism has been confirmed in which the hydrogen bond interaction acts as driving force for excited state proton transfer (ESPT) reaction. In order to provide a reliable description of the reaction energy profiles, we compare the barrier differences obtained by m062x and B3LYP methods. We might safely draw the conclusion that the multiple ESPT is a gradual process initiated by the proton transfer of O7H8⋯N9. And we further proof the ESPT process can be completed via the NHM-2A → NHM-2AS → NHM-2AD → NHM-2AT in S1 state. Theoretical research of NHM-2A has been carried out by density functional theory (DFT) and time-dependent density functional theory (TDDFT). It is worth noting that we predicted that the fluorescence at 400 nm observed in experiment is more likely to be emitted by NHM-2AS in S1 state.

The theoretical study of excited-state intramolecular proton transfer of 2,5-bis(benzoxazol-2-yl)thiophene-3,4-diol.

The symmetrical structures 2,5-bis(benzoxazol-2-yl)thiophene-3,4-diol (BBTD) can take shape two intramolecular hydrogen bonds in chloroform. In order to research the molecular dynamic behavior of BBTD upon photo-induced process, we utilize density functional theory (DFT) and time-dependent density functional theory (TDDFT) to complete theoretical calculation. Through the comparison of bond length, bond angle, IR spectra, and frontier molecular orbitals between ground state (S0) and first excited state (S1), it clearly indicates that photoexcitation have slightly influence for intensity of hydrogen bond. For the sake of understanding the mechanism of excited state intramolecular proton transfer (ESIPT) of BBTD in chloroform, potential energy surfaces have been scanned along with the orientation of O1-H2 and O4-H5 in S0 and S1 state, respectively. A intrigued hydrogen bond dynamic phenomenon has been found that ESIPT of BBTD is not a synergetic double proton transfer process, but a stepwise single proton transfer process BBTD→BBTD-S→BBTD-D. Moreover, the proton transfer process of BBTD-S→BBTD-D is easier to occur than that of BBTD→BBTD-S in S1 state.

Characterization of a dual-CRD galectin in the silkworm Bombyx mori.

Galectins (S-type lectins) are an ancient family of lectins with the ß-galactoside binding activity. In mammals, galectins play essential roles in many biological processes, such as development, immune homeostasis and tumor progression. However, few studies have been devoted to their functions in insects. Here, we characterized the only dual-CRD galectin in the silkworm Bombyx mori (BmGalectin-4). BmGalectin-4 cDNA possesses an open reading frame of 1089 bp, which encodes a putative galectin of 363 amino acids containing tandem carbohydrate recognition domains (CRDs). BmGalectin-4 was expressed in various tissues but the protein was most abundant in fertilized eggs. Its transcript level in fertilized eggs was upregulated upon bacterial challenge. Recombinant BmGalectin-4 purified from Escherichia coli bound to bacterial cell wall components and bacterial cells. In addition, the recombinant protein induced bacterial agglutination, but did not have antibacterial activity against selected microorganisms. Taken together, our results suggest that BmGalectin-4 may function as a pattern recognition receptor primarily in silkworm fertilized eggs.

Identification of C-type lectin-domain proteins (CTLDPs) in silkworm Bombyx mori.

C-type lectins (CTLs) represent a large family of proteins that can bind carbohydrate moieties normally in a calcium-dependent manner. CTLs play important roles in mediating cell adhesion and the recognition of pathogens in the immune system. In the present study, we have identified 23 CTL genes in domestic silkworm Bombyx mori. CTL-domain proteins (CTLDPs) are classified into three groups based on the number of carbohydrate-recognition domains (CRDs) and the domain architectures. These include twelve CTL-S (Single-CRD), six immulectins (Dual-CRD) and five CTL-X (CRD with other domains). We studied their phylogenetic features, analyzed the conserved residues, predicted tertiary structures, and examined the tissue expression profile and immune inducibility. Through bioinformatics analysis, we have putatively identified ten secretory and two cytoplasmic CTL-S; four secretory and two cytoplasmic immulectins; one secretory, one cytoplasmic and three transmembrane forms of CTL-X. Most B. mori CTLDPs form monophyletic groups with orthologs from Lepidoptera, Diptera, Coleoptera and Hymenoptera species. Immulectins of B. mori and Manduca sexta evolved from common ancestor genes perhaps due to gene duplication events of CTL-S ancestor genes. Homology modeling revealed that the overall structures of B. mori CTL domains are analogous to those of humans with a variable loop region. We examined the expression profile of CTLDP genes in naïve and immune-stimulated tissues. The expression and induction of CTLDP genes were related to the tissues and microorganisms. Together, our gene identification, sequence comparison, phylogenetic analysis, homology modeling and expression analysis laid a good foundation for the further studies of B. mori CTLDPs and comparative genomics.

Epidemiology and microbiology of sepsis in mainland China in the first decade of the 21st century.

OBJECTIVES: This study describes the epidemiological and microbiological profile of sepsis during the first decade of the 21(st) century in mainland China. METHODS: The sepsis-related mortality data from 2003 and 2007 were retrieved from the China Health Statistical Yearbook. The microbiology data were retrieved and selected from a literature search of the China Academic Journal Database between 2001 and 2009. A meta-analysis was performed to synthesize the available data on the proportion of positive blood cultures in septic patients and the microorganism distribution. RESULTS: The sepsis mortality in small and medium-sized cities and rural areas declined obviously over time. The mortality of the subpopulations aged 1-54 years tended to be lower than the national averages. In contrast, the sepsis mortality among neonates and the elderly (≥75 years) was obviously higher than national averages. While the mortality in the elderly declined between 2003 and 2007, the neonate sepsis mortality increased dramatically, especially among male neonates. The overall positivity of blood culture were 17.0%, 13.3% and 10.6% among neonatal, pediatric and adult patients with suspected sepsis, respectively; this proportion tended to decrease over time. Among identified microorganisms, the proportions of Gram (+) and (-) bacteria were similar (47.2% vs. 44.5%) among adult patients, while Gram (+) bacteria was predominant among neonatal (77.4%) and pediatric (73.2%) patients and increased in prevalence over time. The positivity of blood cultures and proportions of microorganisms varied by geographical region across mainland China. Sepsis with fungus was rare but was more prevalent in adult sepsis patients (6.4%) than in neonatal patients (0.8%). CONCLUSIONS: The difference in sepsis mortality between urban and rural areas decreased over time. Males, the elderly, and neonates were found to be high-risk subpopulations. Gram (+) bacteria were predominant among neonates with sepsis, but the proportion of patients with Gram (+) or Gram (-) bacteria was similar among adults with sepsis.

Reasons for exclusion of 6820 umbilical cord blood donations in a public cord blood bank.

BACKGROUND: To provide information for umbilical cord blood (UCB) banks to adopt optimal collection strategies and to make UCB banks operate efficiently, we investigated the reasons for exclusion of UCB units in a 3-year recruitment period. STUDY DESIGN AND METHODS: We analyzed records of the reasons for exclusion of the potential UCB donation from 2004 to 2006 in the Tzu-Chi Cord Blood Bank and compared the results over 3 years. We grouped these reasons for exclusion into five phases, before collection, during delivery, before processing, during processing, and after freezing according to the time sequence and analyzed the reasons at each phase. RESULTS: Between 2004 and 2006, there were 10,685 deliveries with the intention of UCB donation. In total, 41.2% of the UCB units were considered eligible for transplantation. The exclusion rates were 93.1, 48.4, and 54.1% in 2004, 2005, and 2006, respectively. We excluded 612 donations from women before their child birth, 133 UCB units during delivery, 80 units before processing, 5010 units during processing, and 421 units after freezing. There were 24 UCB units with unknown reasons of ineligibility. Low UCB weight and low cell count were the first two leading causes of exclusion (48.6 and 30.9%). The prevalence of artificial errors, holiday or transportation problem, low weight, and infant problems decreased year after year. CONCLUSION: The exclusion rate was high at the beginning of our study as in previous studies. Understanding the reasons for UCB exclusion may help to improve the efficiency of UCB banking programs in the future.

[Ageing down-modulates the immune responses to Schistosoma japonicum infection in mice].

OBJECTIVE: To investigate the effect of ageing on the immune responses against Schistosoma japonicum infection in mice. METHODS: Female BALB/c mice were divided into young group (2 months) and old group (18 months), each composed of 8 mice. Each mouse was percutaneously infected with 40 +/- 1 S. japonicum cercariae. At 6 weeks post-infection, the mice were sacrificed, and the spleens were removed and single-cell suspensions of splenocytes were prepared. Worms were perfused from hepatic portal system and counted. The number of eggs in the liver was determined after KOH digestion. Mean single-egg granulomas sizes were determined in stained histological sections. Splenocyte proliferation responses were analyzed by MTT colorimetry. Level of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) in the splenocyte culture supernatants was determined by ELISA. RESULTS: The worm burden and egg per gram of liver in old mice [19.75 +/- 1.95, (1.59 +/- 1.05) x 10(4)] were significantly lower than that of young mice [26.00 +/- 2.42, (208 +/- 0.87) x 10(4)] (P < 0.05). The mean volume of single-egg granulomas of the livers in old mice [(30.13 +/- 10.97) x 10(3) mm3] was significantly lower than that of the young mice [(47.02 +/- 24.13) x l0(3) mm3] (P < 0.05). RESULTS: of T cell proliferation showed that the splenocytes had poorer immune reactivity to ConA in old mice (SI: 1.08 +/- 0.12) than that in young mice (SI: 131 +/- 0.14) (P < 0.05). Levels of IFN-gamma and IL-4 in the splenocyte culture supernatants [(24.05 +/- 6.24), (4.15 +/- 0.68) pg/ml] from old mice were lower than that of young mice [(34.25 +/- 869), (7125 +/- 0.83) pg/ml](P < 0.05). CONCLUSION: Ageing down-modulates the immune responses and the poorer immune reactivity might decrease pathological alterations in mice infected with Schistosoma japonicum.